results from previous studies showed 79% of all high school
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Results from previous studies showed 79% of all high school seniors from a certain city plan to attend college after graduation. A random sample of 200 high school seniors from this city reveals that 162 plan to attend college. Does this indicate that the percentage has increased from that of previous studies? Test at the 5% level of significance.
What is your conclusion?
A.Cannot determine
B.Do not reject H0. There is not enough evidence to support the claim that the proportion of students planning to go to college is greater than .79.
C.More seniors are going to college
D.Reject H0. There is enough evidence to support the claim that the proportion of students planning to go to college is now greater than .79.
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Question 2 of 20
1.0 Points
A manufacturer of flashlight batteries took a sample of 13 batteries from a day’s production and used them continuously until they failed to work. The life lengths of the batteries, in hours, until they failed were: 342, 426, 317, 545, 264, 451, 1049, 631, 512, 266, 492, 562, and 298.
At the .05 level of significance, is there evidence to suggest that the mean life length of the batteries produced by this manufacturer is more than 400 hours?
A.No, because the test value 1.257 is greater than the critical value 1.115
B.Yes, because the test value 1.257 is less than the critical value 1.782
C.No, because the p-value for this test is equal to .1164
D.Yes, because the test value 1.257 is less than the critical value 2.179
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Question 3 of 20
1.0 Points
The form of the alternative hypothesis can be:
A.two-tailed
B.one-tailed
C.neither one nor two-tailed
D.one or two-tailed
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Question 4 of 20
1.0 Points
A lab technician is tested for her consistency by taking multiple measurements of cholesterol levels from the same blood sample. The target accuracy is a variance in measurements of 1.2 or less. If the lab technician takes 16 measurements and the variance of the measurements in the sample is 2.2, does this provide enough evidence to reject the claim that the lab technician’s accuracy is within the target accuracy?
At the a = .01 level of significance, what is your conclusion?
A.Cannot determine
B.Do not reject H0. At the \f$\alpha \f$ = .01 level of significance there is not sufficient evidence to suggest that this technician’s true variance is greater than the target accuracy.
C.Reject H0. At the \f$\alpha \f$ = .01 level of significance, there is enough evidence to support the claim that this technician’s variance is larger than the target accuracy.
D.
Reject H0. At the \f$\alpha \f$ = .01 level of significance, there is not enough evidence to support the claim that this technician’s true variance is larger than the target accuracy.
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Question 5 of 20
1.0 Points
A lab technician is tested for her consistency by taking multiple measurements of cholesterol levels from the same blood sample. The target accuracy is a variance in measurements of 1.2 or less. If the lab technician takes 16 measurements and the variance of the measurements in the sample is 2.2, does this provide enough evidence to reject the claim that the lab technician’s accuracy is within the target accuracy?
State the null and alternative hypotheses.
A.H0: s2 < 1.2, H1: s2 ≠ 1.2
B.H0: s2 ≠ 1.2, H1: s2 = 1.2
C.H0: s2 ≤ 1.2, H1: s2 > 1.2
D.H0: s2 ≥ 1.2, H1: s2 ≠ 1.2
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Question 6 of 20
1.0 Points
Which of the following statements are true of the null and alternative hypotheses?
A.It is possible for neither hypothesis to be true
B.It is possible for both hypotheses to be true
C.Both hypotheses must be true
D.Exactly one hypothesis must be true
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Question 7 of 20
1.0 Points
In an article appearing in Today’s Health a writer states that the average number of calories in a serving of popcorn is 75. To determine if the average number of calories in a serving of popcorn is different from 75, a nutritionist selected a random sample of 20 servings of popcorn and computed the sample mean number of calories per serving to be 78 with a sample standard deviation of 7.
State the null and alternative hypotheses.
A.H0: \f$\mu \f$ \f$\leq \f$ 75, H1: \f$\mu \f$ > 75
B.H0: \f$\mu \f$ \f$\geq \f$ 75, H1: \f$\mu \f$ < 75
C.H0: \f$\mu \f$ = 75, H1: \f$\mu \f$ > 75
D.H0: \f$\mu \f$ = 75, H1: \f$\mu \f$ ≠ 75
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Question 8 of 20
1.0 Points
The “Pizza Hot” manager commits a Type I error if he/she is
A.staying with old style when new style is better
B.switching to new style when it is no better than old style
C.staying with old style when new style is no better than old style
D.switching to new style when it is better than old style
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Question 9 of 20
1.0 Points
Which of the following values is not typically used for f$alpha f$ ?
A.0.50
B.0.10
C.0.05
D.0.01
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Question 10 of 20
1.0 Points
Smaller p-values indicate more evidence in support of the:
A.quality of the researcher
B.null hypothesis
C.the reduction of variance
D.alternative hypothesis
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Question 11 of 20
1.0 Points
You conduct a hypothesis test and you observe values for the sample mean and sample standard deviation when n = 25 that do not lead to the rejection of H0. You calculate a p-value of 0.0667. What will happen to the p-value if you observe the same sample mean and standard deviation for a sample size larger than 25?
A.The p – value may increase or decrease
B.The p – value increases
C.The p – value decreases
D.The p – value stays the same
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Part 2 of 3 –
Question 12 of 20
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
A statistician wishes to test the claim that the standard deviation of the weights of firemen is greater than 25 pounds. To do so, she selected a random sample of 20 firemen and found s = 27.2 pounds.
Assuming that the weights of firemen are normally distributed, to test her research hypothesis the statistician would use a chi-square test. In that case, what is the computed test value?
Place your answer, rounded to 3 decimal places, in the blank. For example, 23.456 would be a legitimate entry.
Question 13 of 20
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
A survey determines that mint chocolate chip is the favorite ice cream flavor of 6% of consumers. An ice cream shop determines that of 260 customers, 20 customers stated their preference for mint chocolate chip.
Find the P-value that would be used to determine if the percentage of customers who prefer mint chocolate chip ice has increased at a 5% level of significance.
P-value: Round your answer to four decimal places as necessary.
Question 14 of 20
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
The ABC battery company claims that their batteries last at least 100 hours, on average. Your experience with their batteries has been somewhat different, so you decide to conduct a test to see if the company’s claim is true. You believe that the mean life is actually less than the 100 hours the company claims. You decide to collect data on the average battery life (in hours) of a random sample of n = 20 batteries. Some of the information related to the hypothesis test is presented below.
Test of H0: f$mugeq f$ 100 versus H1: f$mu< f$ 100
Sample mean 98.5
Std error of mean 0.777
Assuming the life length of batteries is normally distributed, what is the value of the test statistic used to conduct your test of hypothesis? Place your answer, rounded to 3 decimal places in the blank. For example, -2.345 would be a legitimate entry.
Question 15 of 20
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
Suppose a firm that produces light bulbs wants to know whether it can say that its light bulbs typically last more than 1500 hours. Hoping to find support for their claim, the firm collects a random sample of n = 25 light bulbs and records the lifetime (in hours) of each bulb. The information related to the hypothesis test is presented below.
Test of H0: f$muleq f$ 1500 versus H1:f$mu f$ > 1500
Sample mean 1509.5
Std error of mean 4.854
What is the test value that you would use to conduct this test? Place your answer, rounded to 3 decimal places in the blank. For example, 1.234 would be a legitimate entry.
Question 16 of 20
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
Suppose a firm that produces light bulbs wants to know whether it can say that its light bulbs typically last more than 1500 hours. Hoping to find support for their claim, the firm collects a random sample of n = 25 light bulbs and records the lifetime (in hours) of each bulb. The information related to the hypothesis test is presented below.
Test of H0: f$muleq f$ 1500 versus H1: f$ mu f$ > 1500
Sample mean 1509.5
Std error of mean 4.854
Assuming the life length of this type of lightbulb is normally distributed, what is the p-value associated with this test? Place your answer, rounded to 3 decimal places in the blank. For example, .123 would be a legitimate entry.
Question 17 of 20
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
The ABC battery company claims that their batteries last at least 100 hours, on average. Your experience with their batteries has been somewhat different, so you decide to conduct a test to see if the company’s claim is true. You believe that the mean life is actually less than the 100 hours the company claims. You decide to collect data on the average battery life (in hours) of a random sample of n = 20 batteries. Some of the information related to the hypothesis test is presented below.
Test of H0: f$mugeq f$ 100 versus H1: f$mu< f$ 100
Sample mean 98.5
Std error of mean 0.777
Assuming the life length of batteries is normally distributed, if you wish to conduct this test using a .05 level of significance, what is the critical value that you should use? Place your answer, rounded to 3 decimal places in the blank. For example, -1.234 would be a legitimate entry.
Part 3 of 3 –
Question 18 of 20
1.0 Points
Using the confidence interval when conducting a two-tailed test for the population proportion p, we reject the null hypothesis if the hypothesized value for p falls inside the confidence interval.
True
False
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Question 19 of 20
1.0 Points
The p-value of a test is the smallest level of significance at which the null hypothesis can be rejected.
True
False
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Question 20 of 20
1.0 Points
Using the confidence interval when conducting a two-tailed test for the population mean, we do not reject the null hypothesis if the hypothesized value for f$mu f$ falls between the lower and upper confidence limits.
True
False
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