The following is a frequency distribution of the time in minutes required for a shopper to get through the checkout line at a certain discount store on a weekend. The distribution is a random sample of the weekend shoppers at the store.
a. What is the mean of the data in the frequency distribution?
b. Find the standard deviation of the data.
c. What is the standard error of the mean?
d. Find the interval about the sample mean such that the probability is 0.95 that the true mean lies within the interval.
e. Find the probability that the mean of the population will be less than one minute from the mean of the sample.