EXCEL ASSINGMENTS

Dear Students,

You should upload attachments as a zip file and please do not forget insert comments if required and name your zip file with your student ID number.

Some clear explanations are given to you below :

The file P08_11.xlsx contains the number of arrivals at a turnpike tollbooth for each of four 5-minute intervals for each of 256 days. For this problem, assume that each column, such as arrivals from 8:00 AM to 8:05 AM, is a random sample of all arrivals from the corresponding hour the day, such as 8:00 AM to 9:00 AM. Find a 95% confidence interval for the mean number of arrivals during each corresponding hour of the day, that is, one for 8:00 AM to 9:00 AM to 10:00 AM, and so on.

The Wall Street Journal CEO Compensation Study analyzed CEO pay from many U.S companies with fiscal year 2008 revenue of at least $5 billion that filed their proxy statements between October 2008 and March 2009. The data are in the file P08_25.xlsx.

1. Create a new column, Total, that is the sum of columns D and E.
2. After combining Telecommunications and Technology into a single company type, there are nine company types. For each of these, find a 95% confidence interval for the difference between the mean of Total for that company type and mean of Total for all other company types. Comment on what these nine confidence intervals indicate about CEO pay in different industries.

The file P09_01.xlsx contains a random sample of 100 lightbulb lifetimes. The company that produces these lightbulbs wants to know whether it can claim that its lightbulbs typically last more than 1000 burning hours.

1. Identify the null and alternative hypotheses for this situation.
2. Can this lightbulb manufacturer claim that its lightbulbs typically last more than 1000 hours at the 5% significance level? What about at the 1% significance level? Explain your answers.

The human resources manager of DataCom, Inc., wants to examine the relationship between annual salaries (Y) and the number of years employees have worked at DataCom (X). These data have been collected for a sample of employees and are given in columns B and C of the file P10_05.xlsx

1. Estimate the relationship between Y and X. Interpret the least squares line.
2. How well does estimated simple linear regression equation fit the given data? Provide evidence for your answer.

Butler Trucking Company is an independent trucking company in southern California. A major portion of Butler’s business involves deliveries throughout its local area. To develop better work schedules, the managers want to estimate the total daily travel times for their drivers. The managers believe that the total daily travel times (denoted by y) are closely related to the number of miles traveled in making the daily deliveries (denoted by x). Using regression analysis, you should develop an equation showing how depenedent variable y is related to the independent variables (xi’s).

Hint : Miles and Deliveries are independent variables (xi’s), time is independent variable (y).

Please do not forget use StatTool, it can be really helpful to prepare for your second midterm on 6th December.

       Please do not forget assignments can not be submitted after the close date.

Good Luck,

Best,

Berna