binomial, geometric and poisson distributions in excel
DESCRIPTION
Binomial, Geometric and Poisson Distributions with ExcelTRANSCRIPT
B. Heard(Not to be posted, used, etc. without
my permission, students may download one copy for personal use)
Binomial, Geometric and Poisson Distributions in Excel
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 requirementYou 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)
Binomial, Geometric and Poisson Distributions with Excel
Before we start, follow these instructions carefullyGo to
http://highered.mcgraw-hill.com/sites/0070620164/student_view0/excel_templates.html
A picture follows on the next page
This is what it should look like, it is a long page, I couldn’t capture it all…
Binomial, Geometric and Poisson Distributions with Excel
Now click on the link that says “Binomial”Choose/Click “Open”
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1
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
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We a r e “ u n p r o t e c t i n g ” t h e s h e e t s o w e c a n i n p u t o u r o n v a l u e s .
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
Binomial, Geometric and Poisson Distributions with Excel
Now go back to the webpage
Binomial, Geometric and Poisson Distributions with Excel
Now click on the link that says “Geometric”Choose/Click “Open”
2
1
Binomial, Geometric and Poisson Distributions with Excel
When it opens, click on the “Review” tab and then click “Unprotect Sheet”
12
We a r e “ u n p r o t e c t i n g ” t h e s h e e t s o w e c a n i n p u t o u r o n v a l u e s .
Binomial, Geometric and Poisson Distributions with Excel
Now save your Excel Workbook file as something like “Geometric_Calculator”
We need to add one more
Binomial, Geometric and Poisson Distributions with Excel
Now go back to the webpage
Binomial, Geometric and Poisson Distributions with Excel
Now click on the link that says “Poisson”Choose/Click “Open”
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Binomial, Geometric and Poisson Distributions with Excel
When it opens, click on the “Review” tab and then click “Unprotect Sheet”
12
We a r e “ u n p r o t e c t i n g ” t h e s h e e t s o w e c a n i n p u t o u r o n v a l u e s .
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
Binomial, Geometric and Poisson Distributions with Excel
Binomial Distribution Example
Binomial, Geometric and Poisson Distributions with Excel
Page 204, Example 2, a binomial
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
Don’t forget to hit the enter
key after inputting
Binomial, Geometric and Poisson Distributions with Excel
IMPORTANTDON’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
Binomial, Geometric and Poisson Distributions with Excel
The probability of exactly 2 is to the right of 2 under the P(exactly x) columnCheck the book, we nailed it! Our answer is 0.4219. they noted 0.422 (they just rounded)
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
Binomial, Geometric and Poisson Distributions with Excel
Geometric Distribution Example
Binomial, Geometric and Poisson Distributions with Excel
Page 218, Example 1, a geometric
Binomial, Geometric and Poisson Distributions with Excel
Open your Excel File “Geometric_Calculator”
Input 0.74 for p and hit ENTER
Don’t forget to hit the enter
key after inputting!!!!!!
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 = 0.0630Again we nailed it!Note you are given the mean, variance and standard deviation of a geometric distribution with p = 0.74 above also.
Binomial, Geometric and Poisson Distributions with Excel
Poisson Distribution Example
Binomial, Geometric and Poisson Distributions with Excel
Page 220, Example 3, a Poisson example (It is pronounced “Poy-zahn”)
Binomial, Geometric and Poisson Distributions with Excel
Open your Excel File “Poisson_Calculator”Input 3.6 for the Mean and hit ENTER
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.
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.
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)
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
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.”
Binomial, Geometric and Poisson Distributions with Excel