Excel Spreadsheet: Discrete ProbabilityALL.xlsx
Another way to download the Excel Workbook is to click here.
How to use the Excel Spreadsheet Provided
To compute the probability of an event using the Excel spreadsheet provided
- First, download the Excel spreadsheet.
- Then click on the Binomial Probability Distrib tab.
- Then enter the sample size in cell B1, and enter the probability of success in cell B2. Hit the Enter key to recalculate the spreadsheet.
Suppose the probability that a customer will purchase your product if they stay more than ten minutes on your website is 0.68. You take a sample of 20 people and you want to know what is the probability that exactly twelve people will make a purchase, P(X = 12).
To compute the probability do the following.
- Enter the sample size in cell B1, and enter the probability of success in cell B2.
- Move down column A to x = 12, in cell A16.
- Then move to the right to column B.
- The probability that x is equal to 12 is 0.1354.
- In column C, the likelihood that 12 or fewer customers make a purchase is 0.2922. This value is equal to all the probabilities from x = 0 to x=12.
- To determine the mean, variance, and standard deviation, look at cells F1 thru F3.
Suppose you ten people visited Company ABC's website. In the past, 49% of the people who visited the website made a purchase. Determine the following:
- The average number of people who will make a purchase;
- The standard deviation of the people who will make a purchase;
- The probability that exactly five people will make a purchase;
- The likelihood that less than four people made a purchase; and
- Compute the probability that at least six people make a purchase.
First, click the Binomial Probability Distrib. tab at the bottom of the Excel spreadsheet. Note the following.
n = 10, p = .49
Enter 10 in cell B1 and 0.49 in cell B2. Make sure you hit the Enter key after entering each cell. To delete a value in a cell double click the cell.
- The average number of people who will make a purchase is 4.90.
- The standard deviation of the people who will make a purchase is 2.499.
- P(X = 5) = 0.2456
- P(X<4) = P( X< 3) = 0.1888
- P(X > 6) = 1 - P(X < 5) = 1 - 0.6474 = 0.3526
View the video below to see how to use the Excel Spreadsheet provided to compute binomial probabilities.
Video of how to use Excel Spreadsheet