1. What is the 95% CI for the difference between the meanstarting salaries of those who stay at least three years and thosewho leave before 3 years?  Can you say that you are 95%sure there is a difference?

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