In an effort to estimate the proportion of female shoppers at a particular store,175 customers were randomly selected,of which 110 were female.Which of the following would represent a 90% confidence interval around this sample proportion?
A)$0.629 \mp 0.072$
B)$110 \mp 1.64$
C)$0.629 \mp 0.036$
D)$0.629 \mp 1.64$
E)$0.629 \mp 0.060$

Question

Quizplus · Accepted Answer

The sample proportion is 110/175 = 0.629. The standard error for a proportion is calculated as sqrt[(p(1-p))/n], and for a 90% confidence interval, the z-score is approximately 1.645. Calculating the margin of error gives approximately 0.060.

In an Effort to Estimate the Proportion of Female Shoppers 0.629∓0.0720.629 \mp 0.0720.629∓0.072

In an Effort to Estimate the Proportion of Female Shoppers $0.629 \mp 0.072$