What changes the width of a confidence interval A marketing

Last updated: 12/18/2023

What changes the width of a confidence interval A marketing director wants a 95 confidence interval for the mean cost of running shoes She randomly samples 40 pairs of shoes and finds that the sample mean was 122 with a samp standard deviation s of 27 The marketing director concluded with 95 confidence that between 113 36 and 130 64 contains the mean cost of all running shoes What would change for a narrower confidence interval Select all answers that will make the width narrower If the sample size increased to 50 pairs of shoes If she increased the confidence level to a 99 confidence level If the sample size decreased to 30 pairs of shoes If the sample standard deviation was smaller If the point estimate was smaller If the sample standard deviation was larger If she decreased the confidence level to a 90 confidence interval If the point estimate was larger