Question

In a survey of 3123 ​adults, 1492 say they have started paying bills online in the last year.

1. Construct a​ 99% confidence interval for the population proportion. ______-

2. Interpret the results. (multiple choice)

A. The endpoints of the given confidence interval show that adults pay bills online​ 99% of the time.

B.With​ 99% confidence, it can be said that the population proportion of adults who say they have started paying bills online in the last year is between the endpoints of the given confidence interval.

C.With​ 99% confidence, it can be said that the sample proportion of adults who say they have started paying bills online in the last year is between the endpoints of the given confidence interval.

Answer 1

(1)

n = 3123

= 1492/3123 = 0.478

= 0.01

From Table,critical values of Z = 2.576

Confidence Interval:

Answer is:

(0.455, 0.501)

(b)

Correct option:

B.With​ 99% confidence, it can be said that the population proportion of adults who say they have started paying bills online in the last year is between the endpoints of the given confidence interval.