SOLUTION: A researcher claims that the average age of people who buy lottery tickets is 65. A sample of 30 is selected and their ages are recorded as shown below. The standard deviation is 6

Algebra ->  Probability-and-statistics -> SOLUTION: A researcher claims that the average age of people who buy lottery tickets is 65. A sample of 30 is selected and their ages are recorded as shown below. The standard deviation is 6      Log On


   

Question 617087: A researcher claims that the average age of people who buy lottery tickets is 65. A sample of 30 is selected and their ages are recorded as shown below. The standard deviation is 6. At a = 0.05 is there enough evidence to reject the researcher’s claim?
49
63
90
52
22
80
72
56
82
56

24
46
70
74
70
61
65
71
39
74

79
76
71
49
62
68
71
67
69
45
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi, 

A researcher claims that the average age of people who buy lottery tickets is 65

Sample mean of the 30 ages is 62.4 and sample SD = 16

z = %2862.4+-+65%29%2F%2816%2Fsqrt%2830%29%29= -.89

Sample size 30, Degree of Freedom 29,  a = 0.05%, (z = -2.05)

NOT enough evidence to reject researcher's claim