3. Excel steps to find the probability for the weekly incomes of shift supervisors that are between $1000 and $1100 are as follows:

a. Select Insert Function. From the Or select a category list, select Statistical. In the Select a function list, click NORM.DIST. Click OK.

b. Enter 1100 for X, 1000 for the Mean, 100 for the Standard_dev, 1 for Cumulative and click OK.

c. The result will be in your spreadsheet. The answer is 0.8413. Since NORM.DIST is a cumulative function, it measures the total area to the left of $1100 (the area in the lower tail). To find the area under the curve between $1000 (the mean) and $1100 (x), subtract the area to the left of the mean (0.5). This gives 0.8413 − 0.5 = 0.3413.