Question

1. A report claims that 7.3% of vehicle fatalities involve motorcyclists. An insurance investigator studies 50 randomly selected accidents and finds that 5 fatalities implicated motorcyclists. At α=0.05, is there significant evidence that the report is incorrect? Hypothesis Test (Four steps)

Answer 1

Solution :

Given that ,

n = 50

x = 5

1 ) The null and alternative hypothesis is

H0 : p = 0.073

Ha : p 0.073

This is the two tailed test .

= x / n = 5 / 50 = 0.1

P0 = 7.3% = 0.073

1 - P0 = 1 - 0.073 = 0.927

Test statistic = z

= - P0 / [P0 * (1 - P0 ) / n]

= 0.1 - 0.073 / [0.073 (1 . 0.073) / 50]

= 0.734

2 ) The test statistic 0.734

3 ) P-value = 0.4630

= 0.05

0.4630 > 0.05

P-value >  

4 ) Fail to reject the null hypothesis .

There is not sufficient evidence to test the claim .