Sample Size Calculation Problems



1.    Assume that previous fast food research has shown that 80% of the consumers like curlicue French fries.  The researcher wishes to have an error of 6% or less and be 95% confident of an estimate to be made about curlicue french fry consumption from a survey.  What sample size is necessary?



  1. A researcher at Walt Disney World knows wants to determine the average number of rides that a person visiting the Magic Kingdom takes on a one-day visit.  They know that some people do not go on any of the rides while others may get on as many as 27 in a single day.  The researcher wishes to have an error of +/- 2 rides and wishes to be 99% confident.  What sample size is required?



  1. Mom & Pop Store, a small retailer located in Wherever, VA wants to determine whether or not customers who participate in their Mom & Pop Rewards Program are satisfied with the benefits and services provided by the program.  Rather than survey all 1750 of their customers who participate in the program, they’d like to conduct a sample.  They have never conducted a survey before so they have no idea what percent of their customers are satisfied.  The owners of Mom & Pop Store would like to be 95% confident in the results with error of  +/- 5%.  What sample size is required?