The Girl Scouts Would Like to Estimate the Proportion of People

Multiple Choice

The Girl Scouts would like to estimate the proportion of people who consider Thin Mints to be their favorite Girl Scout cookie. A pilot sample of 60 cookie customers found that 15 favored Thin Mint cookies. The total sample size needed to construct a 90% confidence interval for the proportion of customers who favor Thin Mint cookies with a margin of error equal to 6% is ----.

A) 141
B) 270
C) 235
D) 187