# public school final enrollment (C16)

In this activity, you will compare population parameters calculated from the entire dataset with statistics calculated from samples taken from the dataset.

1. Using the textbook dataset, find the mean, median, range and standard deviation for each of these variables. Notice that these are population parameters.

• *public school final enrollment (C16),
• *SAT grand total average score (C21)
• *public school expenditures (C18).

2. Use the Minitab software to obtain a 20% sample from the dataset and calculate the statistics for the same three variables. Answer the following questions using your results.

a. For both the population and the sample, which variable has the most variability? The least variability? Describe any differences that you observe.

b. Compare the means from the 20% sample with the means for the entire sample for each of the 3 variables. How does the variability you noted in part 2a affect the means that you see?

c. How does the variability of a variable effect a sample’s accuracy? Cite evidence from your analyses to support your answer.