Question

During a blood-donor program conducted during finals week for college students, a blood-pressure reading is taken first, revealing that out of 200 donors, 28 have hypertension. All answers to three places after the decimal. A 95% confidence interval for the true proportion of college students with hypertension during finals week is (WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. , WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. ). We can be 80% confident that the true proportion of college students with hypertension during finals week is WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. with a margin of error of WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. . Unless our sample is among the most unusual 10% of samples, the true proportion of college students with hypertension during finals week Is between WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. and WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. . The probability, at 60% confidence, that a given college donor will have hypertension during finals week is WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. , with a margin of error of WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. . Assuming our sample of donors is among the most typical half of such samples, the true proportion of college students with hypertension during finals week is between WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. and WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. . We are 99% confident that the true proportion of college students with hypertension during finals week is WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. , with a margin of error of WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. . Assuming our sample of donors is among the most typical 99.9% of such samples, the true proportion of college students with hypertension during finals week is between WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. and WebAssign will check your answer for the correct number of significant figures. Incorrect: Your answer is incorrect. . Covering the worst-case scenario, how many donors must we examine in order to be 95% confident that we have the margin of error as small as 0.01? Incorrect: Your answer is incorrect. Using a prior estimate of 15% of college-age students having hypertension, how many donors must we examine in order to be 99% confident that we have the margin of error as small as 0.01? Incorrect: Your answer is incorrect.

Answer 1

95% confidence interval

The confidence interval for the proportion is obtained using the formula,

Where,

80% confidence interval

most unusual 10% of samples (90% confidence interval)

60% confidence interval

Among the most typical half of such samples (50% confidence interval)

99% confidence interval

99.9% confidence interval

Sample size

Sample size (prior estimate of proportion = 15%)