Question

A safety group claims that the mean speed of drivers on a highway exceeds the posted speed limit of 65 miles per hour (mph). To investigate the safety group's claim, a random sample of 25 drivers is taken and the sample mean and sample standard deviation are 69 and 8 respectively. Does this give us evidence that the safety group's claim is correct? Give the null and alternative hypotheses for this test. OA. HON 569, H > 69 O B. Hau 2 65, H1-H < 65 OCHO:>65, Haus 65 OD. HO P = 69, H2> 69 E. HON 565, Hiiu>65 QUESTION 17 In a test of significance of How 550 versus Hall> 50 and a test statistic t= 0.15 and n = 75, the p-value is A very close to 1 B. very close to 0.5 C very close to o

Answer 1

Ans:- Given that to claim that mean speed of drivers on highway exceeds the pasted speed limit of 65 miles per hours (mph) random sample (n)=25 sample mean (X) = 69 Somple standard devicetion 8 the null f alternative hypothesis OE. Hoill565 Hii eloos test statistic t= -ll h=25 . Sish Critical value for right teiled test ta12,df dfan-1 df = 24 X=0.05 --txia, df = 1.711 to 69-65 85 t=2.5 Concluded that t=2.5>tc=1711 then conclude that null hypothesis is rejected : mean speed of drivers on highway exceeds the posted speed. Q. 17. Given that t= 0.15 n=75 id fent:df=74 Ho:4250 us Hiiel >50 from hypothesis we say that it is one-tailed test +- value for right twiled test is 0.4405 B. very close to 0.5