Question

For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.

In a marketing survey, a random sample of 1012 supermarket shoppers revealed that 272 always stock up on an item when they find that item at a real bargain price.

(a) Let p represent the proportion of all supermarket shoppers who always stock up on an item when they find a real bargain. Find a point estimate for p. (Round your answer to four decimal places.)


(b) Find a 95% confidence interval for p. (Round your answers to three decimal places.)

lower limit
upper limit

Give a brief explanation of the meaning of the interval.

We are 95% confident that the true proportion of shoppers who stock up on bargains falls outside this interval.We are 5% confident that the true proportion of shoppers who stock up on bargains falls above this interval.    We are 5% confident that the true proportion of shoppers who stock up on bargains falls within this interval.We are 95% confident that the true proportion of shoppers who stock up on bargains falls within this interval.

(c) As a news writer, how would you report the survey results on the percentage of supermarket shoppers who stock up on items when they find the item is a real bargain?

Report p̂.Report the margin of error.    Report the confidence interval.Report p̂ along with the margin of error.

What is the margin of error based on a 95% confidence interval? (Round your answer to three decimal places.)

Answer 1

We are 95% confident that the true proportion of shoppers who stock up on bargains falls within this interval.