Question

In a survey of 850 students in a school, 90% reported having pets at home. If the margin of error is 3.4%, what is the interval that is likely to contain the exact percent of all people who have pets at home?

Between 3.4% and 90%
Between 90% and 93.4%
Between 86.6% and 90%
Between 86.6% and 93.4%

Answer 1

Between 86.6% and 93.4%

Explanation:

To obtain the population proportion from the sample, we calculate the confidence interval ;

Confidence interval = phat ± margin of error

Phat = 90% ; margin of error = +3.4%

90% ± 3.4%

(90 - 3.4)% ; (90 + 3.4)%

86.6% ; 93.4%