Question

Below are matched pair data consisting of driving test scores for a sample of 10 licensed drivers before and after they took an online traffic safety class. At a 0.05 significance level, use the sign test to test the claim that taking this online class affects driving test scores.

Before	40	53	44	62	38	52	61	57	45	56
After	40	51	48	59	34	48	64	52	50	56

(a) What is the value of the test statistic used in this sign test?

(b) What is the critical value in this sign test?

(c) What is the correct conclusion of this sign test?

• There is not sufficient evidence to support the claim that the online class affects driving test scores.
• There is sufficient evidence to support the claim that the online class affects driving test scores.
• There is sufficient evidence to warrant rejection of the claim that the online class affects driving test scores.
• There is not sufficient evidence to warrant rejection of the claim that the online class affects driving test scores.

Answer 1

Probability

Below are matched pair data consisting of driving test scores for a sample of 10 licensed drivers before and after they took an online traffic safety class.

Before	40	53	44	62	38	52	61	57	45	56
After	40	51	48	59	34	48	64	52	50	56

Table for calculating mean and standard deviation :

Before (X)	After (Y)	d = X-Y	d^2
40	40	0	0
53	51	2	4
44	48	-4	16
62	59	3	9
38	34	4	16
52	48	4	16
61	64	-3	9
57	52	5	25
45	50	-5	25
56	56	0	0
		d = 6	d^2 = 120

Fail to reject the null hypothesis

Conclusion : There is not sufficient evidence to warrant rejection of the claim that the online class affects driving test scores.