Question1. In a large clinical trial,

394,519

children were randomly assigned to two groups. The treatment group consisted of

198,154

children given a vaccine for a certain disease, and

36

of those children developed the disease. The other

196,365

children were given a placebo, and

136

of those children developed the disease. Consider the vaccine treatment group to be the first sample. Complete parts (a) through (d) below.

Question2. Since an instant replay system for tennis was introduced at a major tournament, men challenged

1400

referee calls, with the result that

421

of the calls were overturned. Women challenged

751

referee calls, and

217

of the calls were overturned. Use a

0.05

significance level to test the claim that men and women have equal success in challenging calls. Complete parts (a) through (c) below.

Question3. Test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, P-value, and then state the conclusion about the null hypothesis, as well as the final conclusion that addresses the original claim. Among

2100

passenger cars in a particular region,

241

had only rear license plates. Among

302

commercial trucks,

42

had only rear license plates. A reasonable hypothesis is that commercial trucks owners violate laws requiring front license plates at a higher rate than owners of passenger cars. Use a

0.05

significance level to test that hypothesis.a. Test the claim using a hypothesis test.b. Test the claim by constructing an appropriate confidence interval.

Question4. A study was done using a treatment group and a placebo group. The results are shown in the table. Assume that the two samples are independent simple random samples selected from normally distributedpopulations, and do not assume that the population standard deviations are equal. Complete parts (a) and (b) below. Use a

0.01

significance level for both parts.

Treatment Placebo H1 H2 n 34 37 X 1 2.32 2.69 S 0.84 0.54