Question

HW9: Problem 6 Previous Problem Problem List Next Problem (2 points) Among drivers who have had a car crash in the last year, 230 were randomly selected and categorized by age, with the results listed in the table below. Age Under 25 25-44 45-64 Over 64 Drivers 90 51 34 55 If all ages have the same crash rate, we would expect (because of the age distribution of licensed drivers) the given categories to have 16%, 44%, 27%, 13% of the subjects, respectively. At the 0.025 significance level, test the claim that the distribution of crashes conforms to the distribution of ages. The test statistic is x2 = The conclusion is O A. There is sufficient evidence to warrant the rejection of the claim that the distribution of crashes conforms to the distibuion of ages. OB. There is not sufficient evidence to warrant the rejection of the claim that the distribution of crashes conforms to the distibuion of ages. Note: You can earn partial credit on this problem. Jem Preview My Answers Submit Answers .

Answer 1

H0: The distribution of crashes conforms to the distribution of ages

H1: The distribution of crashes not conforms to the distribution of ages

Let the los be 0.025

	Observed		Expected
	Freq (Oi)	Prob	Freq Ei	(Oi-Ei)^2 /Ei
under 25	90	0.16	36.8	76.9087
25-44	51	0.44	101.2	24.9016
4564	34	0.27	62.1	12.7151
Over 64	55	0.13	29.9	21.0706
Total:	230	1	230	135.5960

Num Categories: 4
Degrees of freedom: 3

Test Statistic, X^2: 135.5960
Critical X^2: 9.348409
P-Value: 0.0000

Since Chi-square value > Chi-square critical value and P-value < alpha 0.025 so reject H0

Thus we conclude that the distribution of crashes not conforms to the distribution of ages

Correct Answer: Option (A)