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To calculate the pooled variance in excel, first enter the sample size and variance of each group into separate columns. Then, calculate the pooled variance by using the formula (n1-1)s1^2 + (n2-1)s2^2 / (n1+n2-2). Finally, use the formula to calculate the pooled variance by entering the sample sizes and variances of each group into the formula. The result will be the pooled variance of the two groups.
In statistics, refers to the average of two or more group variances.
We use the word “pooled” to indicate that we’re “pooling” two or more group variances to come up with a single number for the common variance between the groups.
In practice, pooled variance is used most often in a , which is used to determine whether or not two population means are equal.
The pooled variance between two samples is typically denoted as sp2 and is calculated as:
sp2 = ( (n1-1)s12 + (n2-1)s22 ) / (n1+n2-2)
This tutorial provides a step-by-step example of how to calculate the pooled variance between two groups in Excel.
Step 1: Create the Data
First, let’s create two datasets:
Step 2: Calculate the Sample Size & Sample Variance
Next, let’s calculate the sample size and sample variance for each dataset.
Cells E17:F18 show the formulas we used:
Step 3: Calculate the Pooled Variance
Lastly, we can use the following formula to calculate the pooled variance:
=((B17-1)*B18 + (C17-1)*C18) / (B17+C17-2)
Bonus: You can use this to automatically calculate the pooled variance between two groups.