Solve the problem and state your answer or circle your answer as required.

21) Consider two independent random samples with the following results:

n1 = 561 n2 = 642

p1 = 0.38 p2 = 0.26

Use this data to find the 98% confidence interval for the true difference between the population proportions.

Step 1: Find the point estimate that should be used in constructing the confidence interval.

Answer:

Step 2: Find the margin of error. Round your answer to six decimal places.

Answer:

Step 3: Construct the 98% confidence interval. Round your answers to three decimal places.

Left endpoint: ____ Right endpoint: ____

Solve the problem and state your answer or circle your answer as required.

22) The dosage of a drug in a particular tablet needs to be precise. It is essential that the tablets contain 47.89 mg of the active ingredient with a variance of 0.03. A random sample of 25 tablets finds that the variance of the active ingredient is 0.0069. Does the data suggest at a = 0.01 that the variance of the drug in the tablets is less than the desired amount? Assume the population is normally distributed.

Step 1: State the null and alternative hypotheses. Round to four decimal places when

necessary.

Answer: H0 ___ Ha___

Step 2: Determine the critical value(s) of the test statistic. If the test is two-tailed, separate the values with a comma. Round your answer to three decimal places.

Answer:

Step 3: Determine the value of the test statistic. Round your answer to three decimal places.

Answer:

Step 4: Make the decision

A) Reject Null Hypothesis

B) Do not reject Null Hypothesis

Step 5: What is the conclusion?

A) There is sufficient evidence to show that the amount of active ingredient has a variance that is less than the desired amount.

B) There is not sufficient evidence to show that the amount of active ingredient has a variance that is less than the desired amount.

Solve the problem and state your answer or circle your answer as required.

23) Give two independent random samples with the following results:

n1 = 15, n2 = 14

x1 = 1946, x2 = 158

s1 = 19, s2 = 27

Use this data to find a 99% confidence interval for the true difference between the population means. Assume that population variances are not equal and that the two populations are normally distributed.

Step 1: Find the point estimate that should be used in finding the margin of error.

Answer:

Step 2: Find the margin of error to be used in constructing a 99% confidence interval. Round your answer to six decimal places.

Answer: