Enclosed is a file called EAI. It is identical to the file in chapter 7 of the text with the addition of a
column of random numbers. It contains a population of 2500 managers including their annual salary as
well as whether or not they attended a training program. Using this file, and the given random numbers
answer the following questions (neatly and clearly.) Show work.
1. Using PivotTable, create a crosstab giving salaries in the rows and training program in the
columns. Group the salaries in an appropriate way.
2. Present two line graphs on the same set of axes comparing the salaries for those with and
without the training program.
3. Comment on whether there is a significant difference between the salaries of those who took
the training and those who did not. If so, what is it? Would you recommend taking the
4. Now use the given random numbers to get a random sample of 100 records from the file. List
5. Using this sample, and knowing the population standard deviation to be $4,000, find a 90%
confidence interval for the Annual Salary. Does your interval contain the population mean? Is it
possible that it would not? If it is possible that it does not contain the population mean, what is
the purpose of getting the interval?
6. How large a sample would be needed in order to get a 90% confidence interval of size $1,000 (so
that the margin of error is 500)?
7. Now, assuming that you have only this random sample (i.e. that the population standard
deviation is not available), find again a 90% confidence for the mean salary in the population.
How and why is your answer different from that of question 5?
8. Using your sample, what it a point estimate of the percentage who took the training program.
9. Give a 90% confidence interval for this percentage.
10. Management would like to show that the mean salary of the population is under $52,000. What
are the hypotheses (What needs to be shown should be in the alternate hypothesis)? What is
the p value? Does the sample support this contention at α=0.10 level? For this question, assume
that the population standard deviation is known and is $4,000.