50 Multiple Questions For Statistics And Probability

50 Multiple Questions For Statistics And Probability

QUESTION 1

Suppose the American Medical Association Center for Health Policy Research included data, by state, on the number of community hospitals and the average patient stay (in days) in its publication. The data (by state) are shown in the table.
Which two states have an unusually high number of hospitals?

 State Hospitals State Hospitals State Hospitals Alabama 330 Colorado 72 Georgia 163 Alaska 16 Connecticut 35 Hawaii 19 Arizona 61 Delaware 8 Idaho 41 Arkansas 88 Dist. of Columbia 11 Illinois 279 California 236 Florida 289 Indiana 113 Iowa 123 Nebraska 90 Rhode Island 12 Kansas 133 Nebraska 21 S.Carolina 68 Kentucky 107 New Hampshire 21 S.Dakota 52 Louisiana 459 New Jersey 96 Tennessee 122 Maine 38 New Mexico 37 Texas 235 Maryland 51 New York 333 Utah 42 Mass. 101 N.Caroline 117 Vermont 15 Michigan 175 N.Dakota 47 Virginia 98 Minnesota 276 Ohio 193 Washington 92 Mississippi 102 Oklahoma 399 W.Virginia 59 Missouri 133 Oregon 66 Wisconsin 478 Montana 53 Pennsylvania 231 Wyoming 27 [removed] a. Florida and Wisconsin [removed] b. Alabama and Arkansas [removed] c. Wisconsin and Louisiana [removed] d. Maine and Iowa [removed] e. none of these choices

4 points

QUESTION 2

In one of the archaeological excavation sites, the artifact density (number of prehistoric artifacts per 10 liters of sediment) was 2.0. Suppose you are going to dig up and examine 40 liters of sediment at this site. Let  r = 0, 1, 2, 3,… be a random variable that represents the number of prehistoric artifacts found in your 40 liters of sediment. Find the probability that you will find 1 or more artifacts in the 40 liters of sediment. Round your answer to the nearest ten thousandth.

 [removed] a. 0.0137 [removed] b. 0.0027 [removed] c. 0.0013 [removed] d. 0.0096 [removed] e. 0.0107

4 points

QUESTION 3

Compute the population standard deviation σ for the following sample data, assuming the sample comprises the entire population. Round your answer to the nearest hundredth.

 x: 21 19 12 30 29 [removed] a. 9.71 [removed] b. 7.46 [removed] c. 8.68 [removed] d. 6.68 [removed] e. 2.29

4 points

QUESTION 4

What is a sampling distribution?

 [removed] a. A set of measurements (or counts), either existing or conceptual [removed] b. A numerical descriptive measure of a sample [removed] c. A conclusion about the value of a population parameter based on information about the corresponding sample statistic and probability [removed] d. A probability distribution for a sample statistic [removed] e. A numerical descriptive measure of a population

4 points

QUESTION 5

To compare two elementary schools regarding teaching of reading skills, 12 sets of identical twins were used. In each case, one child was selected at random and sent to school A, and his or her twin was sent to school B. Near the end of fifth grade, an achievement test was given to each child. The results follow:

 Twin Pair 1 2 3 4 5 6 School A 80 145 118 90 112 118 School B 83 135 115 105 105 113

 Twin Pair 7 8 9 10 11 12 School A 98 112 115 144 124 96 School B 93 87 98 132 135 105

Suppose a sign test for matched pairs with a 5% level of significance is used to test the hypothesis that the schools have the same effectiveness in teaching reading skills against the alternate hypothesis that the schools have different levels of effectiveness in teaching reading skills. Let p denote portion of positive signs when the scores of school B are subtracted from the corresponding scores of school A. Calculate the P-value. Round your answer to four decimal places.

 [removed] a. 0.3001 [removed] b. 0.2501 [removed] c. 0.1251 [removed] d. 0.7499 [removed] e. 0.3071

4 points

QUESTION 6

A data processing company has a training program for new salespeople. After completing the training program, each trainee is ranked by his or her instructor. After a year of sales, the same class of trainees is again ranked by a company supervisor according to net value of the contracts they have acquired for the company. The results for a random sample of 11 salespeople trained in the last year follow, where x is rank in training class and y is rank in sales after 1 year. Lower ranks mean higher standing in class and higher net sales.

 Person 1 2 3 4 5 6 x rank 8 11 2 4 5 3 y rank 7 2 3 6 5 8

 Person 7 8 9 10 11 x rank 7 9 10 1 6 y rank 9 11 10 1 4

Using a 10% level of significance, test the claim that the relation between x and y is monotone (either increasing or decreasing). What is the level of significance α?

 [removed] a. a = 0.10 [removed] b. a = 0.03 [removed] c. a = 0.05 [removed] d. a = 1.00 [removed] e. a = 10.00

4 points

QUESTION 7

Do bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for the Vanguard Total Stock Index (all Stocks). Let y be a random variable representing annual return for the Vanguard Balanced Index (60% stock and 40% bond). For the past several years, assume the following data. Compute the sample mean for x and for y. Round your answer to the nearest tenth.

 x: 11 0 36 22 34 24 25 -11 -11 -22 y: 9 -3 28 14 23 16 14 -3 -4 -9 [removed] a. X = 37.0  and  y = 12.0 [removed] b. X = 65.0  and y = 9.1 [removed] c. X = 10.8  and y = 8.5 [removed] d. X = 152.0  and y = 9.8 [removed] e. X = 8.5  and y = 10.8

4 points

QUESTION 8

Benford’s Law claims that numbers chosen from very large data files tend to have “1” as the first nonzero digit disproportionately often. In fact, research has shown that if you randomly draw a number from a very large data file, the probability of getting a number with “1” as the leading digit is about 0.301. Suppose you are an auditor for a very large corporation. The revenue report involves millions of numbers in a large computer file. Let us say you took a random sample of n = 247 numerical entries from the file and r = 60 of the entries had a first nonzero digit of 1. Let p represent the population proportion of all numbers in the corporate file that have a first nonzero digit of 1. Test the claim that p is less than 0.301 by using α = 0.1. Are the data statistically significant at the significance level? Based on your answers, will you reject or fail to reject the null hypothesis?

 [removed] a. The P-value is less than the level of significance so the data are statistically significant. Thus, we reject the null hypothesis. [removed] b. The P-value is less than the level of significance so the data are not statistically significant. Thus, we reject the null hypothesis. [removed] c. The P-value is less than the level of significance so the data are statistically significant. Thus, we fail to reject the null hypothesis. [removed] d. The P-value is greater than the level of significance so the data are not statistically significant. Thus, we reject the null hypothesis. [removed] e. The P-value is less than the level of significance so the data are statistically significant. Thus, we reject the null hypothesis.

4 points

QUESTION 9

Suppose the age distribution of the Canadian population and the age distribution of a random sample of 528 residents in the Indian community of Red Lake are shown below.

 Observed Number Age (years) Percent of Canadian Population in Red Lake Village Under 5 6.4% 38 5 to 14 11.8% 48 15 to 64 70.3% 397 65 and older 11.5% 45

Use a = 0.05 to test the claim that the age distribution of the general Canadian population fits the age distribution of the residents of Red Lake Village. Given a value of 9.673 for x2, find (or estimate) the P-value of the sample test statistic.

 [removed] a. 0.01 < P-Value < 0.025 [removed] b. P-Value < 0.005 [removed] c. 0.025 < P-Value < 0.05 [removed] d. 0.25 < P-Value < 0.50 [removed] e. 0.05 < P-Value < 0.10

4 points

QUESTION 10

Identify the level of measurement corresponding to the data “Cost of rod and reel” associated with fishing.

 [removed] a. interval [removed] b. nominal [removed] c. ratio [removed] d. none of these choices [removed] e. ordinal

4 points

QUESTION 11

Data may be classified by one of the four levels of measurement. What is the name of the lowest level?

 [removed] a. nominal [removed] b. ratio [removed] c. ordinal [removed] d. interval [removed] e. simple

4 points

QUESTION 12

Compute the expected age μ of a British nurse in 1851. Assume that the table below shows the age distribution of nurses in Great Britain in 1851. Round your answer to nearest hundredth.

 Age range (yr) 20–29 30–39 40–49 50–59 60–69 70–79 80+ Midpoint (x) 24.5 34.5 44.5 54.5 64.5 75.5 84.5 Percent of nurses 5.7% 9.6% 19.5% 29.1% 24.9% 9.0% 2.2% [removed] a. 53.93 [removed] b. 59.50 [removed] c. 43.96 [removed] d. 54.50 [removed] e. 53.96

4 points

QUESTION 13

Wetlands offer a diversity of benefits. They provide habitat for wildlife, spawning grounds for U.S. commercial fish, and renewable timber resources. In the last 200 years the United States has lost more than half its wetlands. Suppose Environmental Almanac gives the percentage of wet lands lost in each state in the last 200 years. Assume that for the lower 48 states, the percentage loss of wetlands per state is as follows:

 46 37 36 42 81 20 73 59 35 50 87 52 24 27 38 56 39 74 56 31 27 91 46 9 54 52 30 33 28 35 35 23 90 72 85 42 59 50 49 48 38 60 46 87 50 89 49 67

The distribution is approximately mound shaped.

 [removed] a. True [removed] b. False

4 points

QUESTION 14

1.      Wing Foot is a shoe franchise commonly found in shopping centers across the United States. Wing Foot knows that its stores will not show a profit unless they gross over \$940,000 per year. Let A be the event that a new Wing Foot store grosses over \$940,000 its first year. Let B be the event that a store grosses over \$940,000 its second year. Wing Foot has an administrative policy of closing a new store if it does not show a profit in either of the first two years. Assume that the accounting office at Wing Foot provided the following information: 56% of all Wing Foot stores show a profit the first year; 75% of all Wing Foot store show a profit the second year (this includes stores that did not show a profit the first year); however, 80% of Wing Foot stores that showed a profit the first year also showed a profit the second year. Compute P(A and B), if P(A) = 0.56, P(B) = 0.75 and P(B|A) = 0.80. Round your answer to the nearest hundredth.

 [removed] a. 0.8 [removed] b. 0.51 [removed] c. 0.7 [removed] d. 0.45 [removed] e. 0.94

4 points

QUESTION 15

1.      How hot does it get in Death Valley? Assume that the following data are taken from a study conducted by the National Park System, of which Death Valley is a unit. The ground temperaturesoF  were taken from May to November in the vicinity of Furnace Creek. Compute the median for these ground temperatures. Round your answer to the nearest tenth.

 148 151 168 173 194 178 193 194 178 178 168 163 151 144 [removed] a. 170.5 [removed] b. 193.5 [removed] c. 341 [removed] d. 168 [removed] e. 159.5

4 points

QUESTION 16
Assume that the following data represent baseball batting averages (multiplied by 1000) for a random sample of National League players near the end of the baseball season. The frequency table showing class limits, class boundaries, midpoints and frequency is given below. Draw a histogram.

 Boundaries Midpoint Frequency

4 points

QUESTION 17

1.      There are 4 radar stations and the probability of a single radar station detecting an enemy plane is 0.55. Make a histogram for the probability distribution.

 r p(r) 0 0.041 1 0.200 2 0.368 3 0.300 4 0.092

4 points

QUESTION 18

1.      Richard has been given a 9-question multiple-choice quiz in his history class. Each question has three answers, of which only one is correct. Since Richard has not attended the class recently, he doesn’t know any of the answers. What is the value of p? (p is the value of success) Round your answer to the nearest tenth.

 [removed] a. 0.3 [removed] b. 9 [removed] c. 3 [removed] d. 2.7 [removed] e. 27

4 points

QUESTION 19

In baseball, is there a linear correlation between batting average and home run  percentage? Let x represent the batting average of a professional baseball player. Let y represent the home run percentage (number of home runs per 100 times at bat). Suppose a random sample of baseball players gave the following information.

 x 0.251 0.259 0.29 0.265 0.269 y 1.3 3.7 5.8 3.9 3.7

Make a scatter diagram for the data. Draw the line that best fits the data.

4 points

QUESTION 20

Sand and clay studies were conducted at a site in California. Twelve consecutive depths, each about 15 cm deep, were studied and the following percentages of sand in the soil were recorded.

 33.7 26.9 31.2 27 33.1 27.7

 34.0 24.7 33.7 32.8 25.8 28.8

Convert this sequence of numbers to a sequence of symbols A and B, where A indicates a value above the median and B denotes a value below the median gives ABABABABAABB. The number of runs is 10. What is the lower critical number c1?

 [removed] a. 1 [removed] b. 4 [removed] c. 2 [removed] d. 5 [removed] e. 3

4 points

QUESTION 21

The probability of a single radar station detecting an enemy plane is 0.75 and the probability of not detecting an enemy plane is 0.25. How many such stations are required to be 98% certain that an enemy plane flying over will be detected by at least one station?

 [removed] a. 2 [removed] b. none of these choices [removed] c. 3 [removed] d. 4 [removed] e. 1

4 points

QUESTION 22

A professional employee in a large corporation receives an average of μ = 42.7 e-mails per day. Most of these e-mails are from other employees in the company. Because of the large number of e-mails, employees find themselves distracted and are unable to concentrate when they return to their tasks. In an effort to reduce distraction caused by such interruptions, one company established a priority list that all employees were to use before sending an e-mail. One month after the new priority list was put into place, a random sample of 38 employees showed that they were receiving an average of x = 35.3 e-mails per day. The computer server through which the e-mails are routed showed that σ = 19.6. Has the new policy had any effect? Use a 5% level of significance to test the claim that there has been a change (either way) in the average number of e-mails received per day per employee. What is the value of the test statistic?

 [removed] a. –0.061 [removed] b. 0.378 [removed] c. –2.327 [removed] d. 0.061 [removed] e. 2.327

4 points

QUESTION 23

What was the age distribution of nurses in Great Britain at the time of Florence Nightingale? Thanks to Florence Nightingale and the British census of 1851, we have the following information (based on data from classic text Notes on Nursing, by Florence Nightingale). Note: In 1851 there were 25,466 nurses in Great Britain. Furthermore, Nightingale made a strict distinction between nurses and domestic servants. Find the probability that a British nurse selected at random in 1851 would be 70 years of age or older. Round your answer to nearest thousandth.

 Age range (yr) 20–29 30–39 40–49 50–59 60–69 70–79 80+ Midpoint (x) 24.5 34.5 44.5 54.5 64.5 75.5 84.5 Percent of nurses 5.7% 9.7% 19.5% 29.2% 25.0% 9.1% 1.8% [removed] a. 0.091 [removed] b. 0 [removed] c. 0.099 [removed] d. 0.105 [removed] e. 0.109

4 points

QUESTION 24

Independent random samples from two regions in the same area gave the following chemical measurements (ppm). Assume the population distributions of the chemical are mound-shaped and symmetric for these two regions.
Region I: ;
981 726 686 496 657 627 815 504 950 605 570 520
Region II: ;

1024 830 526 502 539 373 888 685 868 1093 1132 792 1081 722 1092 844
Let  be the population mean and  be the population standard deviation for . Let  be the population mean and  be the population standard deviation for . Determine and examine the 90% confidence interval for . Does the interval consist of numbers that are all positive? all negative? or different signs? At the 90% level of confidence, is one region more interesting that the other from a geochemical perspective?

 [removed] a. The interval contains both positive and negative numbers. We can say at the required confidence level that one region is more interesting than the other. [removed] b. The interval contains only positive numbers. We can say at the required confidence level that one region is more interesting than the other. [removed] c. The interval contains only negative numbers. We cannot say at the required confidence level that one region is more interesting than the other. [removed] d. The interval contains only positive numbers. We cannot say at the required confidence level that one region is more interesting than the other. [removed] e. The interval contains both positive and negative numbers. We cannot say at the required confidence level that one region is more interesting than the other.

4 points

QUESTION 25

When do creative people get their good ideas? Assume that the survey of 963 inventors gives the following information:

 Time of Day When Good Ideas Occur Time Number of Inventors 6 A.M. – 12 noon 281 12 noon – 6 P.M. 120 6 P.M. – 12 midnight 320 12 midnight – 6 A.M. 242

Assuming that the time interval includes the left limit and all the times up to but not including the right limit, estimate the probability that an inventor has a good idea during the time interval from 6 A.M. to 12 noon. Write your answer as a fraction in simplest form.

4 points

QUESTION 26

The systolic blood pressure of individuals is thought to be related to both age and weight. Let the systolic blood pressure, age, and weight be represented by the variables x1x2, and x3, respectively. Suppose that Minitab was used to generate the following descriptive statistics, correlations, and regression analysis for a random sample of 15 individuals.

 Descriptive Statistics Variable N Mean Median TrMean StDev SE Mean x1 15 159.35 159.65 159.35 3.401 0.878134 x2 15 72.77 73.77 72.77 1.722 0.444618 x3 15 185.90 185.20 185.90 4.266 1.101476

 Variable Minimum Maximum Q1 Q3 x1 126 173 140.497 166.049 x2 45 89 47.721 78.484 x3 129 249 140.492 222.010

 Correlations (Pearson) x1 x2 x2 0.848 x3 0.817 0.634

Regression Analysis

The regression equation is
x1 = 0.703 + 1.388x2 + 0.907x

 Predictor Coef StDev T P Constant 0.703 0.495 1.42 0.091 x2 1.388 0.669 2.07 0.030 x3 0.907 0.390 2.33 0.019 S = 0.424 R-sq = 92.5 % R-sq(adj) = 91.1 %

Test the coefficient of  in the regression equation to determine if it is zero or not zero. Use a level of significance of 5%.  Do you accept or reject the null hypothesis that the coefficient should equal zero?

 [removed] a. accept [removed] b. reject

4 points

QUESTION 27

How much should a healthy Shetland pony weigh? Let x be the age of the pony (in months), and let y be the average weight of the pony (in kilograms). Suppose a random sample of ponies gave the following information.

 x 4 7 14 19 21 y 50 85 130 160 175

Make a scatter diagram for the data.4 points

QUESTION 28

Draw a tree diagram to display all the possible head-tail sequences that can occur when you flip a coin foour times.

 [removed] a. [removed] b. [removed] c. [removed] d. [removed] e.

4 points

QUESTION 29

Suppose automobile insurance companies gave annual premiums for top-rated companies in several states. The figure below shows box plots for the annual premium for urban customers in three states.

Which state has the highest median premium?

 [removed] a. Pennsylvania has the highest median premium. [removed] b. California has the highest median premium. [removed] c. Texas as well as California have the highest median premium. [removed] d. Texas has the highest median premium. [removed] e. none of these choices

4 points

QUESTION 30

1.      Assume that the table below shows the age distribution of nurses in Great Britain in 1851. Make a histogram for the probability distribution.

 Age range (yr) 20–29 30–39 40–49 50–59 60–69 70–79 80+ Midpoint (x) 24.5 34.5 44.5 54.5 64.5 75.5 84.5 Percent of nurses 9.8% 5.6% 19.4% 24.9% 29.3% 9.3% 1.7%

4 points

QUESTION 31

The systolic blood pressure of individuals is thought to be related to both age and weight. Let the systolic blood pressure, age, and weight be represented by the variables x1x2, and x3, respectively. Suppose that Minitab was used to generate the following descriptive statistics, correlations, and regression analysis for a random sample of 15 individuals.

 Descriptive Statistics Variable N Mean Median TrMean StDev SE Mean x1 15 155.56 156.06 155.56 3.815 0.985029 x2 15 63.42 64.02 63.42 1.226 0.316552 x3 15 195.04 194.64 195.04 4.164 1.075140

 Variable Minimum Maximum Q1 Q3 x1 126 179 144.445 165.050 x2 42 83 47.888 77.461 x3 120 250 139.698 222.040

 Correlations (Pearson) x1 x2 x2 0.870 x3 0.802 0.517

Regression Analysis

The regression equation is
x1 = 0.804 + 1.308x2 + 0.966x

 Predictor Coef StDev T P Constant 0.804 0.692 1.16 0.134 x2 1.308 0.732 1.79 0.050 x3 0.966 0.705 1.37 0.098 S = 0.319 R-sq = 90.6 % R-sq(adj) = 92.6 %

Relative to its mean, which variable has the smallest spread of data values?

a.       X1

b.      X2

c.       X3

4 points

QUESTION 32

Rothamsted Experimental Station (England) has studied wheat production since 1852. Each year many small plots of equal size but different soil/fertilizer conditions are planted with wheat. At the end of the growing season, the yield (in pounds) of the wheat on the plot is measured. Suppose for a random sample of years, one plot gave the following annual wheat production (in pounds):

 4.28 4.36 4.43 4.92 5.16 4.13 2.52 4.52 4.5 3.02 2.55 3.53 4.75 3.67 3.2 4.38

For this plot, the sample variance is . Another random sample of years for a second plot gave the following annual wheat production (in pounds):

 3.76 3.94 3.95 3.8 3.7 3.74 4.06 3.94 3.98 4.04 3.85 3.94 3.89 4.05 3.88 4.04

For this plot, the sample variance is . Test the claim using  that the population variance of annual wheat production for the first plot is larger than that for the second plot.
What are the degrees of freedom?

 [removed] a. 14;  15 [removed] b. 15;  15 [removed] c. 14;  16 [removed] d. 15;  14 [removed] e. 16;  14

4 points

QUESTION 33

A random sample of  communities in western Kansas gave the following information for people under 25 years of age.

: Rate of hay fever per 1000 population for people under 25

A random sample of   regions in western Kansas gave the following information for people over 50 years old.

: Rate of hay fever per 1000 population for people over 50

Assume that the hay fever rate in each age group has an approximately normal distribution. Do the data indicate that the age group over 50 has a lower rate of hay fever? Use a = 0.05 State the null and alternate hypotheses.

4 points

QUESTION 34

Are customers more loyal in the East or in the West? The following table is based on information from Trends in the United Sates, published by the food marketing Institute, Washington, D.C. The columns represent loyalty (in years) at a primary supermarket. The rows represent regions of the United States.

 Less Than 1 Year 1 – 2 Years 3 – 4 Years 5 – 9 Years 10 – 14 Years 15 or More Years Row Total East 32 54 59 112 77 118 452 Midwest 31 68 68 120 63 173 523 South 53 92 93 158 106 158 660 West 41 56 67 78 45 86 373 Column Total 157 270 287 468 291 535 2008

What is the probability that a customer chosen at random has been loyal 5 or more years given that he or she is from the South? Round your answer to the nearest thousandth.

 [removed] a. 0.210 [removed] b. 0.326 [removed] c. 0.639 [removed] d. 0.417 [removed] e. none of these choices

4 points

QUESTION 35

Assume that about 30% of all U.S. adults try to pad their insurance claims. Suppose that you are the director of an insurance adjustment office. Your office has just received 140 insurance claims to be processed in the next few days. What is the probability that from 45 to 47 of the claims have been padded?

 [removed] a. 0.167 [removed] b. 0.119 [removed] c. 0.104 [removed] d. 0.056 [removed] e. 0.222

4 points

QUESTION 36

What percentage of the general U.S. population have bachelor’s degrees? Suppose that the Statistical Abstract of the United States, 120th Edition, gives the following percentage of bachelor’s degrees by state. For convenience, the data are sorted in increasing order.

 17 18 18 18 19 20 20 20 21 21 21 21 21 22 22 22 22 22 23 23 24 24 24 24 24 25 25 25 25 26 26 26 26 26 26 27 27 27 28 28 28 29 29 31 31 32 32 34 35 38

Illinois has a bachelor’s degree percentage rate of about 18%. Into what quartile does this rate fall?

 [removed] a. second quartile [removed] b. first quartile [removed] c. third quartile [removed] d. first quartile as well as second quartile [removed] e. none of these choices

4 points

QUESTION 37

Wing Foot is a shoe franchise commonly found in shopping centers across the United States. Wing Foot knows that its stores will not show a profit unless they gross over \$940,000 per year. Let A be the event that a new Wing Foot store grosses over \$940,000 its first year. Let B be the event that a store grosses over \$940,000 its second year. Wing Foot has an administrative policy of closing a new store if it does not show a profit in either of the first two years. Assume that the accounting office at Wing Foot provided the following information: 61% of all Wing Foot stores show a profit the first year; 72% of all Wing Foot store show a profit the second year (this includes stores that did not show a profit the first year); however, 87% of Wing Foot stores that showed a profit the first year also showed a profit the second year. Compute  if , , and . Round your answer to the nearest hundredth.

 [removed] a. 0.46 [removed] b. 0.44 [removed] c. 0.76 [removed] d. 0.8 [removed] e. 0.87

4 points

QUESTION 38

How long did real cowboys live? One answer may be found in the book The Last Cowboys by Connie Brooks (University of New Mexico Press). This delightful book presents a thoughtful sociological study of cowboys in West Texas and Southeastern New Mexico around the year 1890. Assume that a sample of 32 cowboys gave the following years of longevity:

 59 52 67 86 72 66 99 89 84 91 91 92 69 68 87 86 73 61 71 75 72 73 85 84 91 57 77 76 84 93 58 49

Make a stem-and-leaf display for these data.

 [removed] a. 4 9 = 49 years 4 9 5 9 8 7 2 6 9 8 7 6 1 7 7 6 5 3 3 2 2 1 8 9 7 6 6 5 4 4 4 9 9 9 3 2 1 1 1 [removed] b. 4 9 = 49 years 4 9 5 2 7 8 9 6 1 6 7 8 7 1 2 2 3 3 5 7 8 8 3 4 4 5 6 6 7 9 9 1 1 1 2 3 9 9 [removed] c. 4 9 = 49 years 4 9 5 9 8 7 2 6 8 7 6 1 7 8 6 5 4 3 2 2 1 8 9 7 6 6 5 4 4 3 9 9 9 3 2 1 1 1 [removed] d. 4 9 = 49 years 4 9 5 2 7 8 9 6 1 6 7 8 9 7 1 2 2 3 3 5 6 7 8 4 4 4 5 6 6 7 9 9 1 1 1 2 3 9 [removed] e. none of these choices

4 points

QUESTION 39

Wind Mountain is an archaeological study area located in southwestern New Mexico. Potsherds are broken pieces of prehistoric Native American clay vessels. One type of painted ceramic vessel is called Mimbres classic black-on-white. At three different sites the number of such sherds was counted in local dwelling excavations.

 Site I Site II Site III 51 34 18 46 46 22 57 53 44 44 59 23 18 61 33 40 15

Shall we reject or not reject the claim that there is no difference in population mean Mimbres classic black-on-white sherd counts for the three sites? Test given a = 0.01.
Find (or estimate) the P-value of the sample test statistic.

 [removed] a. P-Value = 0.01 [removed] b. 0.05 < P-Value < 0.1 [removed] c. P-Value = 0.05 [removed] d. P-Value > 0.1 [removed] e. 0.01 < P-Value < 0.05

4 points

QUESTION 40

Jim has a 5-year-old car in reasonably good condition. He wants to take out a \$50,000 term (that is, accident benefit) car insurance policy until the car is 10 years old. Assume that the probability of a car having an accident in the year in which it is x years old is as follows:

 x = age 5 6 7 8 9 P(accident) 0.01182 0.01282 0.01386 0.01513 0.01602

Jim is applying to a car insurance company for his car insurance policy. Using the probabilities that the car will have an accident in its 5th, 6th, 7th, 8th, or 9th year, and the \$50,000 accident benefit, what is the expected loss to Car Insurance Company for the respective years? Round your answers to the nearest dollar.

 [removed] a. \$591, \$641, \$693, \$747, \$801 [removed] b. \$591, \$646, \$693, \$747, \$801 [removed] c. \$591, \$641, \$693, \$757, \$801 [removed] d. \$581, \$641, \$693, \$747, \$801 [removed] e. \$581, \$646, \$693, \$757, \$801

4 points

QUESTION 41

Finish times (to the nearest hour) for 57 dogsled teams are shown below. Use five classes. Categorize the basic distribution shape as uniform, mound-shaped symmetric, bimodal, skewed left, or skewed right.

The relative frequency histogram of the above data is given below.

 [removed] a. Bimodal [removed] b. none of these choices [removed] c. mound-shaped symmetric [removed] d. approximately mound-shaped symmetric [removed] e. Skewed right

4 points

QUESTION 42

Does talking while walking slow you down? Suppose a study considered mean cadence (steps per minute) for subjects using no walking device, a standard walker, and a rolling walker. In addition, the cadence was measured when the subjects had to perform dual tasks. The second task was to respond vocally to a signal or respond to an interview question while walking. Cadence was measured for subjects who were just walking (using no walking device, a standard walker, or a rolling walker), for subjects required to respond to a signal, and for subjects required to respond to an interview question while walking. How many cells are there in the data table?

 [removed] a. 9 [removed] b. 8 [removed] c. 7 [removed] d. 12 [removed] e. 1

4 points

QUESTION 43

John runs a computer software store. He counted 125 people who walked by his store in a day, 51 of whom came into the store. Of the 51, only 23 bought something in the store. Estimate the probability that a person who comes into the store will buy nothing. Round your answer to the nearest hundredth.

 [removed] a. 0.82 [removed] b. 0.59 [removed] c. 0.22 [removed] d. 0.55 [removed] e. none of these choices

4 points

QUESTION 44

Diagnostic tests of medical conditions have several results. The rest result can be positive or negative. A positive test (+) indicates the patient has the condition. A negative test (–) indicates the patient does not have the condition. Remember, a positive test does not prove the patient has the condition. Additional medical work may be required. Consider a random sample of 137 patients, some of whom have a medical condition and some of whom do not. Results of a new diagnostic test for the condition are shown.

 Condition Present Condition Absent Row Total Test Result + 119 18 137 Test Result – 18 46 64 Column Total 137 64 201

Assume that the sample is representative of the entire population. For a person selected at random, find P(getting test result – or condition present). Round your answer to the nearest hundredth.

 [removed] a. 0.91 [removed] b. 0.28 [removed] c. 0.09 [removed] d. 0.13 [removed] e. none of these choices

4 points

QUESTION 45

1.      Suppose a certain species bird has an average weight of x = 3.80 grams. Based on previous studies, we can assume that the weights of these birds have a normal distribution with o = 0.37 grams. For a small group of 10 birds, find the margin of error for a 70% confidence interval for the average weights of these birds.

 [removed] a. 0.06 grams [removed] b. 0.02 grams [removed] c. 1.04 grams [removed] d. 0.12 grams [removed] e. 0.04 grams

4 points

QUESTION 46

Finish times (to the nearest hour) for 57 dogsled teams are shown below. Draw a relative – frequency histogram. Use five classes.

 261 270 236 244 280 296 284 298 289 289 248 256 338 360 341 333 261 267 287 296 313 311 309 309 299 303 277 283 304 305 288 290 288 289 297 299 332 330 309 328 309 328 285 291 295 298 306 315 310 318 318 320 333 321 323 324 327

4 points

QUESTION 47

In one of the archaeological excavation sites, the artifact density (number of prehistoric artifacts per 10 liters of sediment) was . Suppose you are going to dig up and examine  liters of sediment at this site. Let  0, 1, 2, 3,… be a random variable that represents the number of prehistoric artifacts found in your  liters of sediment. Find the probability that you will find fewer than  prehistoric artifacts in the  liters of sediment. Round your answer to the nearest ten thousandth.

4 points

QUESTION 48

1.      A coin is to be tossed 1000 times. What is the probability that the 785th toss is heads?

 [removed] a. 3/4 [removed] b. 0 [removed] c. 1/4 [removed] d. 1/2 [removed] e. 1

4 points

QUESTION 49

1.      If event A is certain to occur, what is P(A)?

 [removed] a. 0.5 [removed] b. 0.25 [removed] c. 0.75 [removed] d. 1 [removed] e. 0

4 points

QUESTION 50

1.      It is thought that prehistoric Indians did not take their best tools, pottery, and household items when they visited higher elevations for their summer camps. It is hypothesized that archaeological sites tend to lose their cultural identity and specific cultural affiliation as the elevation of the site increases. Let x be the elevation (in thousands of feet) for an archaeological site in the southwestern United States. Let y be the percentage of unidentified artifacts (no specific cultural affiliation) at a given elevation. Suppose that the following data were obtained for a collection of archaeological sites in New Mexico:

 x 5.5 6.5 7.5 7.75 8.75 y 15 32 55 39 72

2.
Find a for the equation of the least-squares line y = a + bx.

 [removed] a. 75.923 [removed] b. 42.698 [removed] c. –75.923 [removed] d. –42.698 [removed] e. –42.068

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