Microsoft Office Tutorials and References
In Depth Information
Using NORM. DIST and POISSON. DIST to Determine Probabilities
✓ The second argument is the mean of the Poisson distribution to use.
This too must be an integer value greater than 0.
✓ The third argument is TRUE if you want the cumulative probability and
FALSE if you want the noncumulative probability.
mean of 20.
For example, suppose that you’re the manager of a factory that makes brake
shoes. Your district manager has announced an incentive: You’ll receive a
bonus for each day that the number of defective shoes is less than 20. How
many days a month will you meet this goal, knowing that the average number
of defective brake shoes is 25 per day? Here are the steps to follow:
1. In a new worksheet, enter the average number of defects per day (25)
in a cell.
If desired, enter an adjacent label to identify the cell.
2. In the cell below, type =POISSON.DIST( to start the function entry.
3. Enter the value 20.
4. Enter a comma ( ,).
5. Click the cell where you entered the average defects per day, or enter
its cell address.
6. Enter a comma ( ,).
7. Enter TRUE) .
8. Press Enter to complete the formula.
9. If desired, enter a label in an adjacent cell to identify this as the
probability of 20 or fewer defects.