A survey of households in a small town showed of 1200 sampled households, that in 850 households at least one member attended a town meeting during the year. Using the 99% level of confidence, what is the confidence interval for the proportion of households represented at a town meeting?
A) [0.6745, 0.7421]
B) [0.6550, 0.7050]
C) [0.6659, 0.6941]
D) [0.6795, 0.6805]

Question

Quizplus · Accepted Answer

The sample proportion is 850/1200 = 0.7083. Using the formula for the confidence interval for a proportion and the z-value for 99% confidence (2.576), the interval is calculated as [0.6745, 0.7421].

A Survey of Households in a Small Town Showed of 1200