Question

 

A. Assume that a sample is used to estimate a population proportion p. Find the 99% confidence interval for a sample of size 161 with 119 successes. Enter your answer as an open-interval (i.e., parentheses) using decimals (not percents) accurate to three decimal places. 99% C.I. = ___

B. Out of 600 people sampled, 372 preferred Candidate A. Based on this, estimate what proportion of the voting population (ππ) prefers Candidate A.
Use a 90% confidence level, and give your answers as decimals, to three places.___< pie<___

C. You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately p∗=28%p∗=28%. You would like to be 99.5% confident that your esimate is within 2.5% of the true population proportion. How large of a sample size is required? n =___

D. Giving a test to a group of students, the grades and gender are summarized below

	A	B	C	Total
Male	17	15	16	48
Female	7	6	9	22
Total	24	21	25	70

Let ππ represent the percentage of all female students who would receive a grade of B on this test. Use a 95% confidence interval to estimate ππ to three decimal places.
Enter your answer as a tri-linear inequality using decimals (not percents). ___

Answer 1

Only A and B have been solved. Please post each question separately. It helps to answer in details

A. Assume that a sample is used to estimate a population proportion p. Find the 99% confidence interval for a sample of size 161 with 119 successes. Enter your answer as an open-interval (i.e., parentheses) using decimals (not percents) accurate to three decimal places. 99% C.I. = ___

The problem is solved in excel and to help you understand better the formulas method is also given below. hope it helps.

B. Out of 600 people sampled, 372 preferred Candidate A. Based on this, estimate what proportion of the voting population (ππ) prefers Candidate A.
Use a 90% confidence level, and give your answers as decimals, to three places.___< pie<___