Solutions Statistics

The 1967 Age Discrimination in Employment Act (ADEA) made it illegal to discriminate against workers

Question: The 1967 Age Discrimination in Employment Act (ADEA) made it illegal to discriminate against workers 40 years of age and older. Opponents of the law argue that there are sound economic reasons why employers would not want to hire and train workers who are very close to retirement. They also argue that people’s abilities tend to deteriorate with age. In fact, Forbes (Dec. 13, 1999) reported that 25-year-olds did significantly better than 60-year-olds on the Wechsler Adult Intelligence Scale, the most popular IQ test. The data IQ.Xls provides raw test scores for a sample of 36 25-year-olds and 36 60-year-olds.

a) Estimate the mean raw test score for all 25-year-olds using a 99% confidence interval. Give an interpretation of the confidence interval. [Use the t-distribution.]

b) Find a 95% confidence interval for the mean raw score of all 60-year-olds and interpret your results. [Use the t-distribution].

Data IQ.Xls IQ25	IQ60
54	42
59	60
82	73
49	34
70	45
75	45
61	54
68	49
47	28
86	33
72	61
60	37
80	38
66	51
81	65
55	40
63	47
58	27
92	22
76	60
77	65
82	28
50	30
49	40
41	58
82	45
88	60
45	36
52	45
63	37
63	37
80	42
94	34
51	60
67	45
68	58