For this problem, carry at least four digits after the decimal in your calculations. In a marketing survey, a random sample of 1002 supermarket shoppers revealed that 270 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.
(b) Find a 95% confidence interval for p.
Give a brief explanation of the meaning of the interval.
a. 5% of all confidence intervals would include the true proportion of shoppers who stock up on bargains.
b. 95% of the confidence intervals created using this method would include the true proportion of shoppers who stock up on bargains.
c. 95% of all confidence intervals would include the true proportion of shoppers who stock up on bargains.
d. 5% of the confidence intervals created using this method ould include the true proportion of shoppers who stock up on bargains.
(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?
A. Report p.
B. Report p along with the margin of error.
C. Report the margin of error.
D. Report the confidence interval.
What is the margin of error based on a 95% confidence interval?