Question

in a poll of 517 human resource professionals, 45.6% said that body piercings and tattoos were big personal grooming red flags. complete parts (a) through (d) below.
.428 < p <.484
(round to three decimal places as needed.)
d. compare the confidence intervals from parts (b) and (c) and identify the interval that is wider. why is it wider?
○ a. the 99% confidence interval is wider than the 80% confidence interval. a confidence interval must be wider in order to be more confident that it captures the true value of the population proportion.
○ b. the 99% confidence interval is wider than the 80% confidence interval. a confidence interval must be wider in order to be less confident that it captures the true value of the population proportion.
○ c. the 80% confidence interval is wider than the 99% confidence interval. a confidence interval must be wider in order to be more confident that it captures the true value of the population proportion.
○ d. the 80% confidence interval is wider than the 99% confidence interval. a confidence interval must be wider in order to be less confident that it captures the true value of the population proportion.

Explanation:

A higher confidence level requires a wider interval. The 99% confidence interval is more confident (higher level) than the 80% confidence interval. So, it must be wider to be more likely to capture the true population proportion.

Answer:

A. The 99% confidence interval is wider than the 80% confidence interval. A confidence interval must be wider in order to be more confident that it captures the true value of the population proportion.