Question

A grocery store chain has been tracking data on the number of shoppers that use coupons. The data shows that 71% of all shoppers use coupons. 18 times out of 20 these results were considered accurate to within 2.5%

Answer 1

The question deals with statistics, specifically involving survey data about the percentage of grocery shoppers using coupons, margin of error, and sampling techniques.

Step-by-step explanation:

The student is asking about the concept of statistics and how to determine the accuracy of a survey in relation to the population it represents. Specifically, the question is about the percentage of grocery shoppers that use coupons based on data collected and the associated margin of error. To address the problem, one would typically use methods such as confidence intervals and hypothesis testing to assess the reliability and accuracy of the survey data compared to the actual population statistics. Additionally, the question also involves the understanding of proportions and sampling techniques that are fundamental topics in statistical analysis. Examples given in the question refer to collecting data on shoppers, surveying families about stock ownership, and analyzing the mean discount offered by coupons, all of which are practical applications of statistical methods.

Answer 2

The computation for the confidence level = (18/20) x 100% = 90 %, the E or the margin error = 0.023 and the p = to 0.71. Confidence interval can be achieved by using the formula (p-E, p+E) = (0.71-0.025, 0.71+0.025). Therefore, the confidence interval is (0.685,0.735).