Statistics How To

Binomial Probabilities in Minitab: Find in Easy Steps

Binomial Theorem > Binomial probabilities in Minitab

 

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How to Find Binomial Probabilities in Minitab

binomial probabilities in minitab

A Binomial Distribution) shows either (S)uccess or (F)ailure.


Binomial probability is a way of calculating the probability of an event happening in a binomial trial (i.e. a trial with only two possible outcomes, like tossing a coin). How you find binomial probabilities in Minitab depends on which type of event you have:

  1. The probability of a single event (i.e. X=3)
  2. The probability of a cumulative event (i.e. X ≥3)
  3. The value “X” for a known probability (i.e. what is the value of X when p=.90?)


The probability of a single event: X=3, n=10, p(0.15)

Step 1: Click “Calc,” mouse over “Probability Distributions” and then click “Binomial.”
Step 2: Click the “Probability” radio button.
Step 3: Type the number of trials “n” into the Number of Trials box. for this sample question, the number of trials is 10.
Step 4: Type the probability “p” into the Event probability box. for this sample question, the probability is 0.15.
Step 5: Click the “Input Constant” radio button and then type your X-value into the box. For this example question, X=3.
Step 6: Click “OK.”

The probability of a cumulative event: X ≥3, n=10, p(0.15)

Step 1: Click “Calc,” mouse over “Probability Distributions” and then click “Binomial.”
Step 2: Click the “Cumulative Probability” radio button.
Step 3: Type the number of trials “n” into the Number of Trials box. for this sample question, the number of trials is 10.
Step 4: Type the probability “p” into the Event probability box. for this sample question, the probability is 0.15.
Step 5: Click the “Input Constant” radio button and then type your X-value into the box. For this example question, X≥3, so type “3” into the box.
Step 6: Click “OK.”

The value “X” for a known probability (i.e. what is the value of X when p=.90?)

Step 1: Click “Calc,” mouse over “Probability Distributions” and then click “Binomial.”
Step 2: Click the “Inverse cumulative Probability” radio button.
Step 3: Type the number of trials “n” into the Number of Trials box. for this sample question, the number of trials is 10.
Step 4: Type the probability “p” into the Event probability box. for this sample question, the probability is 0.15.
Step 5: Click the “Input Constant” radio button and then type your X-value into the box. For this example question, the probability we want to know X for is .90, so type “.90” into the box.
Step 6: Click “OK.” Note: Minitab will calculate a range of two values: choose the X value that’s closest to the probability you’re looking for.

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Binomial Probabilities in Minitab: Find in Easy Steps was last modified: October 12th, 2017 by Stephanie Glen

2 thoughts on “Binomial Probabilities in Minitab: Find in Easy Steps

  1. Josef

    Hello,
    Thanks for your good work.
    For P(X >= 3), shouldn’t the probability be one minus the value obtained from Minitab?
    Best regards,
    Josef

  2. Andale Post author

    Hi, Josef,
    I actually don’t have a copy of Minitab any more, but from what I remember, I think Minitab should still give you the correct P (i.e. no need to subtract from 1).