Question

Suppose a study estimated that 85% of the residents of a town (with an error range of ±12 percentage points at 95% confidence) favor building a new community center. Which of the following percentages of the town's residents may favor building a new community center?

A. 69%
B. 79%
C. 59%
D. 99%

Answer 1

B. 79%

Explanation:

yes

Answer 2

The confidence interval for a given sample value can be calculated using the following formula:

Confidence interval = Average value ± Margin of error

Which in this case the values are:

Average value = 85%

Margin of error = 12%

Therefore substituting the given values into the equation will give us:

Confidence interval = 85 ± 12

Confidence interval = 73, 97

Therefore the percentage of the residents of the town who are favour of building a new community center ranges from 73% to 97%.

Based from the given choices, only letter B 79% is within this range:

Answer:

B. 79%