This document provides instructions for downloading and using Excel templates to calculate binomial, geometric, and Poisson distributions. It demonstrates how to access and set up the templates from a website. Examples are worked through for each distribution type to show how values can be input and the relevant probabilities calculated. The templates also automatically provide additional descriptive statistics for the distributions.

1. Binomial, Geometric and Poisson
Distributions in Excel
B. Heard
(Not to be posted, used, etc. without my
permission, students may download one copy
for personal use)

2. Binomial, Geometric and Poisson Distributions with Excel
 What I am about to show you, will amaze you.
 However…
 If your instructor has told you that you MUST use
Minitab, I can’t change that requirement
 You could still use these “Magic Calculators” to
check your work.
 I think it is important for you to be familiar with
Excel, since that is what you have access to in the
work environment (Microsoft Excel)

3. Binomial, Geometric and Poisson Distributions with Excel
 Before we start, follow these instructions carefully
 Go to http://highered.mcgraw-
hill.com/sites/0070620164/student_view0/excel_tem
plates.html
 A picture follows on the next page

4. Binomial, Geometric and Poisson Distributions with Excel
 This is what it should look like, it is a long page, I
couldn’t capture it all…

5. Binomial, Geometric and Poisson Distributions with Excel
 Now click on the link that says “Binomial”
 Choose/Click “Open”
1
2

6. Binomial, Geometric and Poisson Distributions with Excel
 When it opens, click on the “Review” tab and then
click “Unprotect Sheet” – You must do this step
1
2

7. Binomial, Geometric and Poisson Distributions with Excel
 Now save your Excel Workbook file as something
like “Binomial_Calculator”
 Let’s finish setting up our calculators

8. Binomial, Geometric and Poisson Distributions with Excel
 Now go back to the webpage

9. Binomial, Geometric and Poisson Distributions with Excel
 Now click on the link that says “Geometric”
 Choose/Click “Open”
1
2

10. Binomial, Geometric and Poisson Distributions with Excel
 When it opens, click on the “Review” tab and then
click “Unprotect Sheet”
1
2

11. Binomial, Geometric and Poisson Distributions with Excel
 Now save your Excel Workbook file as something
like “Geometric_Calculator”
 We need to add one more

12. Binomial, Geometric and Poisson Distributions with Excel
 Now go back to the webpage

13. Binomial, Geometric and Poisson Distributions with Excel
 Now click on the link that says “Poisson”
 Choose/Click “Open”
1 2

14. Binomial, Geometric and Poisson Distributions with Excel
 When it opens, click on the “Review” tab and then
click “Unprotect Sheet”
1
2

15. Binomial, Geometric and Poisson Distributions with Excel
 Now save your Excel Workbook file as something
like “Poisson_Calculator”
 Let’s use our new calculators now

16. Binomial, Geometric and Poisson Distributions with Excel
Binomial Distribution
Example

17. Binomial, Geometric and Poisson Distributions with Excel
 Page 204, Example 2, a binomial

18. Binomial, Geometric and Poisson Distributions with Excel
 Open your Excel File “Binomial_Calculator”
 Input 3 for n and 0.75 for p and hit ENTER

19. Binomial, Geometric and Poisson Distributions with Excel
 IMPORTANT
 DON’T FORGET TO HIT THE ENTER KEY OR
CLICK ON ANOTHER CELL AFTER YOU INPUT
YOUR VALUE
 DO NOT MESS WITH THE REST OF THE
SHEET, ONLY INPUT INTO GREEN CELLS I
NOTE, YOU WILL HAVE TO DOWNLOAD IT
AGAIN IF YOU INADVERTENTLY CHANGE A
CELL THAT IS USED FOR CALCULATIONS

20. Binomial, Geometric and Poisson Distributions with Excel
Note this calculator also
gives me the mean,
variance and standard
deviation of the binomial
with an n of 3 and p of
0.75
The probability of
exactly 2 is to the
right of 2 under
the P(exactly x)
column
Check the book,
we nailed it! Our
answer is 0.4219.
they noted 0.422
(they just
rounded)

21. Binomial, Geometric and Poisson Distributions with Excel
Geometric Distribution
Example

22. Binomial, Geometric and Poisson Distributions with Excel
 Page 218, Example 1, a geometric

23. Binomial, Geometric and Poisson Distributions with Excel
 Open your Excel File “Geometric_Calculator”
 Input 0.74 for p and hit ENTER

24. Binomial, Geometric and Poisson Distributions with Excel
The question was to find the
probability that he hits his
first free throw on the third
or fourth attempt so we
have to add the results for
exactly 3 and exactly 4
which is 0.0500 + 0.0130 =
0.0630
Again we nailed it!
Note you are given the
mean, variance and
standard deviation of a
geometric distribution with p
= 0.74 above also.

25. Binomial, Geometric and Poisson Distributions with Excel
Poisson Distribution
Example

26. Binomial, Geometric and Poisson Distributions with Excel
 Page 220, Example 3, a Poisson example (It is
pronounced “Poy-zahn”)

27. Binomial, Geometric and Poisson Distributions with Excel
 Open your Excel File “Poisson_Calculator”
 Input 3.6 for the Mean and hit ENTER

28. Binomial, Geometric and Poisson Distributions with Excel
The question was to find the probability
that 7 rabbits would be found (based on a
Poisson distribution with an average of 3.6)
Look to the right of 7 and under P(Exactly
x) to see 0.0425 is the answer.
Nailed it!
Note you are given the variance and
standard deviation of a Poisson distribution
with Mean = 3.6 above also. What is the
Mean? You input it! It’s 3.6, note the
Variance = Mean on a Poisson distribution
and the standard deviation is just the
square root of that number.

29. Binomial, Geometric and Poisson Distributions with Excel
 The P(At most x) and P(At least x) are very
valuable also. Let’s take a look at the last
problem again where we were looking for rabbits
(Poisson) in a field where an average of 3.6
rabbits/acre were living.

30. Binomial, Geometric and Poisson Distributions with Excel
To the right of 4 and under P(At most x)
would give us the answer to a question that
could be asked a couple of ways:
What is the probability that no more than 4
rabbits were living on a given acre? 0.7064
What is the probability that less than 5
( P(x<5) ) rabbits were living on a given
acre? 0.7064
Basically it gives us P(x≤4) or P(x<5)

31. Binomial, Geometric and Poisson Distributions with Excel
To the right of 6 and under P(At least x)
would give us the answer to a question that
could be asked a couple of ways:
What is the probability that more than 5
rabbits ( P(x>5) ) were living on a given
acre? 0.0733
What is the probability that at least 6 rabbits
were living on a given acre? 0.0733
Basically it gives us P(x≥6) or P(x>5)
BASED ON THE MEAN WE INPUT

32. Binomial, Geometric and Poisson Distributions with Excel
 Good luck, I hope this helps.
 If you enjoy reading the humor of an absent
minded math professor, come be a fan at
www.facebook.com/cranksmytractor or visit me at
www.CranksMyTractor.com where I write about
everyday things I come across…
 My best to you all…
“Statistics do not lie, but people do.”