Employee Retention at D&Y Demand for systems analysts in the consulting industry is greater than ever. Graduates with a combination of business and computer knowledge, some even from liberal arts programs, are getting great offers form consulting companies. Once these people are hired, they frequently switch from one company to another as competing companies lure them away with even better offers. One consulting company, D&Y, has collected data on a sample of systems analysts with undergraduate degrees they hired several years ago. The data are in the file C08_02.xlsx (Found in BB). The variables are as follows:

Starting salary: employee’s starting salary at D&Y

• On Road Pct: percentage of time employee has spent on the road with clients
• State Univ: whether the employee graduated from State University (D&Y’s principal source of recruits)
• CIS Degree: whether the employee majored in Computer Information Systems (CIS) or a similar computer-related area
• Stayed 3 Years: whether the employee stayed at least 3 years with D&Y
• Tenure: tenure of employee at D&Y (months) if he or she moved before 3 years D&Y is trying to learn everything it can about retention of these valuable employees.

You can help by solving the following problems and then, based on your analysis, presenting a report to D&Y.

1. Although starting salaries are in a fairly-narrow band, D&Y wonders whether they have anything to do with retention.

a. Calculate a 95% confidence interval for the mean starting salary of all employees who stay at least 3 years with D&Y. Do the same for those who leave before 3 years. Then calculate a 95% confidence interval for the difference between these means.

b. Among all employees whose staring salary is below the median ($37,750), calculate a 95% confidence interval for the proportion who stay with D&Y for at least 3 years. Do the same for the employees with starting salaries above the median. Then calculate a 95% confidence interval for the difference between these proportions.

2. D&Y wonders whether the percentage of time on the road might influence who stays and who leaves. Repeat the previous problem but now do the analysis in terms of percentage of time on the road rather than starting salary. (The median percentage of time on the road is 54%.)

3. Find a 95% confidence interval for the mean tenure (in months) of all employees who leave D&Y within 3 years of being hired. Why is it not possible with the given data to calculate a confidence interval for the mean tenure at D&Y among all systems analysis hired by D&Y?

4. State University’s students, particularly those in its nationally acclaimed CIS area, have traditionally been among the best of D&Y’s recruits. But are they relatively hard to retain? Calculate one or more confidence intervals to help you make an argument one way or the other

Employee	Starting Salary	On Road Pct	State Univ	CIS Degree	Stayed 3 Years	Tenure
4	35700	29%	No	Yes	Yes
7	37300	41%	Yes	No	Yes
11	37800	73%	No	Yes	Yes
13	36100	56%	Yes	Yes	Yes
14	36100	42%	Yes	Yes	Yes
15	33800	35%	No	Yes	Yes
16	38900	36%	No	Yes	Yes
18	37600	58%	No	Yes	Yes
19	38100	78%	Yes	Yes	Yes
20	38300	16%	No	No	Yes
21	34600	29%	No	Yes	Yes
22	36300	26%	No	Yes	Yes
24	37700	55%	Yes	Yes	Yes
28	36700	56%	Yes	Yes	Yes
36	36900	42%	No	Yes	Yes
40	40600	70%	Yes	Yes	Yes
41	41600	63%	Yes	Yes	Yes
42	40800	44%	No	No	Yes
45	36100	56%	Yes	Yes	Yes
46	36100	42%	No	Yes	Yes
48	39100	38%	No	Yes	Yes
49	40300	53%	Yes	Yes	Yes
50	38800	78%	Yes	Yes	Yes
52	38400	23%	No	Yes	Yes
53	35200	33%	No	Yes	Yes
54	36100	24%	No	No	Yes
55	37100	44%	No	Yes	Yes
57	36800	46%	Yes	No	Yes
58	36500	27%	No	No	Yes
59	35900	29%	No	No	Yes
63	36700	37%	No	Yes	Yes
65	38200	62%	Yes	Yes	Yes
1	38900	57%	Yes	Yes	No	11
2	42300	68%	Yes	Yes	No	5
3	39800	75%	No	Yes	No	21
5	40400	71%	No	Yes	No	19
6	36400	62%	No	Yes	No	18
8	36600	37%	No	Yes	No	17
9	34600	65%	No	Yes	No	20
10	42300	53%	Yes	Yes	No	16
12	39700	60%	No	Yes	No	12
17	35500	50%	No	Yes	No	15
23	37200	59%	Yes	Yes	No	14
25	36600	45%	No	Yes	No	13
26	41000	81%	Yes	Yes	No	9
27	40800	111%	Yes	Yes	No	7
29	37700	56%	No	Yes	No	22
30	37700	42%	No	Yes	No	11
31	39300	69%	Yes	Yes	No	16
32	37500	50%	No	Yes	No	18
33	40000	69%	Yes	Yes	No	9
34	41500	64%	Yes	No	No	5
35	39600	72%	No	Yes	No	18
37	39500	62%	No	Yes	No	5
38	37800	20%	No	Yes	No	23
39	38600	57%	No	Yes	No	8
43	36200	68%	No	Yes	No	31
44	39600	59%	No	Yes	No	10
47	39500	53%	Yes	Yes	No	17
51	39400	34%	Yes	Yes	No	27
56	37200	64%	Yes	Yes	No	23
60	37900	76%	Yes	Yes	No	14
61	37900	58%	No	Yes	No	26
62	37900	28%	No	Yes	No	14
64	37400	49%	No	Yes	No	19
66	36600	51%	Yes	Yes	No	7