How to Calculate Probability from Z-Score in Excel (with Quick Steps)

What Is Z-Score?

Z-Score is a special type of value that indicates how far the value is from the mean. The general formula for the Z-score is:

Z represents the value of the Z-score
X is the value of any case
µ stands for the mean value
σ represents the value of the Standard Deviation

Read More: How to Calculate Z Score in Excel

What Is Probability?

Probability represents the possibility of occurring any events with respect to the total number of events. The mathematical expression of probability is:

How to Calculate Probability from Z-Score in Excel with Quick Steps

We’ll consider a dataset of 10 students at a school. The names of the students are in column B and their examination marks are in column C.

Step 1 – Estimate the Mean Value of the Dataset

Select cell F5.
Insert the following formula in the cell.

=AVERAGE(C5:C14)

Press Enter.

Estimate Mean Value of Dataset to Calculate Probability from Z-Score

You will get the value of the mean of our dataset.

Step 2 – Evaluate the Standard Deviation

Select cell F6.
Use the following formula in the cell.

=STDEV.P(C5:C14)

Press the Enter key.

Evaluate Standard Deviation to Calculate Probability from Z-Score

You will get the value of the standard deviation.

Step 3 – Determine the Z-Score

Insert a Column between columns C and D.
Rename the column as Z-Score.

Determine Z-Score Value to Calculate Probability from Z-Score

Select cell D5 and use the following formula in the cell:

=(C5-$G$5)/$G$6

Press Enter.

Determine Z-Score Value to Calculate Probability from Z-Score

Double-click on the Fill Handle icon to copy the formula down to cell D14.

Determine Z-Score Value to Calculate Probability from Z-Score

You will get all the values of Z-Scores for the datasheet.

Step 4 – Calculate the Probability for Each Data Point

Insert a Column between columns D and E.
Rename the column as Probability.

Calculate Probability from Z-Score Value for Each Case

Select cell E5 and insert the following formula for the cell:

=NORM.DIST(C5,$H$5,$H$6,TRUE)

Press Enter.

Calculate Probability from Z-Score Value for Each Case

Double-click on the Fill Handle icon to copy the formula down to cell E14.

Calculate Probability from Z-Score Value for Each Case

You will get all the values of probability.

Interpretation of the Result

We are illustrating the result for cell E5. The value of probability is 0.664. The value means that the possibility of happening that event is 0.664 with respect to the total number of events.

Download the Practice Workbook

Probability from Z-Score.xlsx

<< Go Back to Statistical Significance in Excel | Excel for Statistics | Learn Excel

Get FREE Advanced Excel Exercises with Solutions!