Question

1. A research conducted by the University of Michigan claimed that there are more female drivers in the USA than male drivers. A researcher decides to test this claim on his state. In his simple random sample of 900 observations, he noticed that 468 of 900 were women. At a = 0.05, is there enough evidence to support the claim?

(Use the P-value method where Pz<1.20=0.8849 $Aewt1VsvdyxFQAAAABJRU5ErkJggg==$ )

2. A sample of 100 body temperatures has a mean of 98.8℉ . Assume that σ is known to be 0.6℉ . Use a 0.05 significance level to test the claim that the mean body temperature of the population is equal to 98.6℉ , as is commonly believed. Is there sufficient evidence to conclude that the common belief is wrong?

(Use the P-value method where Pz<3.33=0.9996 )

3. A simple random sample of 25 filtered 100 mm cigarettes is obtained and the tar content of each cigarette is measured. The sample has a mean of 15 mg and a standard deviation of 4 mg. Use a 0.05 significance level to test the claim that the mean tar content of filtered 100 mm cigarettes is less than 20 mg, which is the mean for unfiltered king size cigarettes. What do the results suggest about the effectiveness of the filters?

(The critical value of ? for α=0.05 $Q8Rmv4QQL3tpgAAAABJRU5ErkJggg==$ (single tail) and 24 d.f is - 1.711)

4. A simple random sample of front-seat occupants involved in car crashes is obtained. Among 2500 occupants not wearing seat belts, 15 were killed. Among 7500occupants wearing seat belts, 15 were killed. Use this data with 0.05 significance level to test the claim that the fatality rate is higher for those not wearing seat belts. (Write all necessary steps like Hypotheses, Test Statistic, P-value & Conclusion)

Given thatPz<3.17=0.9992 .

Answer 1

Ho: Nul Hypothests P 40.5 Cpsopo1hon of female Daivers t s less S more p Sample poopo ion-468/0052 Test statist" c 『s. ven p-value ニ'-o. 8sua:0-115) fnce -value O15 is qreater than d 0.O5, the CL diffe ence ts not Sign cant. Fo to refect nu hypothejfsc Thedata donot Suppot the clarm that pxoportHon of female DvesS s mo