A researcher is interested in estimating the average number of times that shoppers have used the buy-online-pickup-in-store (BOPIS) service in the past 3 months. The following standards have been set by her manager: a confidence level of 95% and an error within 0.5 of a time. Suppose she had no information about the population standard deviation for the variable, but knows that the range for the variable is about 30 times. What is the most appropriate sample size