Statistics – Lab Week 4
• Binomial Probability Distribution
Calculating Binomial Probabilities
Open a new MINITAB worksheet.
We are interested in a binomial experiment with 10 trials. First, we will make the
probability of a success ¼. Use MINITAB to calculate the probabilities for this
distribution. In column C1 enter the word ‘success’ as the variable name (in the
shaded cell above row 1. Now in that same column, enter the numbers zero through
ten to represent all possibilities for the number of successes. These numbers will
end up in rows 1 through 11 in that first column. In column C2 enter the words ‘one
fourth’ as the variable name. Pull up Calc > Probability Distributions > Binomial
and select the radio button that corresponds to Probability. Enter 10 for the Number
of trials: and enter 0.25 for the Event probability:. For the Input column:
select ‘success’ and for the Optional storage: select ‘one fourth’. Click the button
OK and the probabilities will be displayed in the Worksheet.
Now we will change the probability of a success to ½. In column C3 enter the
words ‘one half’ as the variable name. Use similar steps to that given above in
order to calculate the probabilities for this column. The only difference is in Event
probability: use 0.5.
Finally, we will change the probability of a success to ¾. In column C4 enter the
words ‘three fourths’ as the variable name. Again, use similar steps to that given
above in order to calculate the probabilities for this column. The only difference is in
Event probability: use 0.75.
Plotting the Binomial Probabilities