Suppose you are conducting a study about how the average US worker spends time over the course of a workday. You are interested in how much time workers spend per day on personal calls, emails, and social networking websites, as well as how much time they spend socializing with coworkers versus actually working. The most recent census provides data for the entire population of U. S. workers on variables such as travel time to work, time spent at work, and break time at work. The census, however, does not include data on the variables you
are interested in, so you obtain a random sample of 83 full-time workers in the United States and ask about persona calls, e-mails, and so forth. you are curious about how your sample compares with the census, so you also ask the workers the same questions about work that are asked in the census.

Suppose the mean time spent at work per day from the most recent census is 8.32 hours, with a standard deviation of 0.91 hours. Your sample of 83 U. S. workers provides a mean time spent at work per day of 8.46 hours with a
sample standard deviation of 0.98 hours.

Organize this information by completing the following table.

μ = M=
σ = s=
σM = sM=