Question

In 2014, a leading financial services provider conducted a survey in order to determine how Americans are planning for retirement. Of the 1,041 adults aged 18 years and older who were included in the survey, 243 said they were currently not saving anything for retirement. Based on this information, the 95% confidence interval for the proportion of all adults who are currently not saving for retirement would be which of the following?

Answer 1

Solution :

Given that,

Point estimate = sample proportion = = x / n = 243/1041 =0.233

1 - = 0.767

Z_/2 = 1.96

Margin of error = E = Z _{/ 2} * (( * (1 - )) / n)

= 1.96 * (((0.233 * 0.767) / 1041)

= 0.026

A 95% confidence interval for population proportion p is ,

- E < p < + E

0.233 - 0.026 < p < 0.266 + 0.026

0.208 < p < 0.259

(0.208 , 0.259)

The 95% confidence