The book Survey Responses: An Evaluation of Their Validity, by E. J. Wentland and K. Smith (Academic Press), includes studies reporting the accuracy of answers to questions from surveys. A study by Locander and others considered the question “Are you a registered voter?” Accuracy of response was confirmed by a check of city voting records. Two methods of survey were used: a face-to-face interview and a telephone interview. A random sample of 93 people were asked the voter registration question face-to-face. Seventy-nine respondents gave accurate answers (as verified by city records). Another random sample of 83 people were asked the same question during a telephone interview. Seventy-four respondents gave accurate answers. Assume that the samples are representative of the general population. (a) Let p1 be the population proportion of all people who answer the voter-registration question accurately during a face-to-face interview. Let p2 be the population proportion of all people who answer the question accurately during a telephone interview. Find a 95% confidence interval for p1 - p2. (b) Does the interval contain numbers that are all positive? all negative? mixed?
The book Survey Responses: An Evaluation of Their Validity, by E. J. Wentland and K. Smith (Academic Press), includes studies reporting the accuracy of answers to questions from surveys. A study by Locander and others considered the question “Are you a registered voter?” Accuracy of response was confirmed by a check of city voting records. Two methods of survey were used: a face-to-face interview and a telephone interview. A random sample of 93 people were asked the voter registration question face-to-face. Seventy-nine respondents gave accurate answers (as verified by city records). Another random sample of 83 people were asked the same question during a telephone interview. Seventy-four respondents gave accurate answers. Assume that the samples are representative of the general population. (a) Let p1 be the population proportion of all people who answer the voter-registration question accurately during a face-to-face interview. Let p2 be the population proportion of all people who answer the question accurately during a telephone interview. Find a 95% confidence interval for p1 - p2. (b) Does the interval contain numbers that are all positive? all negative? mixed?
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 4 images
