Question

A survey reported that 40% of people save loose change to pay bills. The margin of error was given as 3.1 percentage points. Which confidence interval corresponds to the given information

Answer 1

0.369≤
`\mu`≤0.431

Explanation:

The confidence interval boundaries is represented mathematically as shown below;

CI = p±E where;

p is the percentage of people surveyed

E is the margin of error

Given parameters

p = 40% = 0.4

E = 3.1% = 0.031

Required

Confidence interval corresponds to the given information.

Substituting the given parameters into the given formula:

CI = p±E

CI = 0.4±0.031

CI = (0.4-0.031, 0.4+0.031)

CI = (0.369, 0.431)

Hence the confidence interval that corresponds with the information is 0.369≤
`\mu`≤0.431.