A corporation has 2000 male and 500 female engineers. A stratified random sample of 200 male and 50 female engineers gives each engineer 1 chance in 10 to be chosen. This sample design gives every individual in the population the same chance to be chosen for the sample.

Suppose that the employee names are listed so that employees 1 through 2000 are male and employees 2001 through 2500 are female. We will select a simple random sample instead of the stratified sample described above. Enter the numbers 1 to 2500 into an Excel spreadsheet. Choose an SRS of 250 employees by using StatTools>Data Utilites>Random Sample. Select Data > Sort from the menu to sort your samples so that you can easily see how many are male and how many are female. (If StatTools does not let you do this exercise, please use Excel's RAND() function to create random variables between 0 and 1, sort your data and pick the first 250 as your sample.)

a. How many of the individuals selected in your sample are female?

b. How is the stratified sample different from the SRS?