Pooled Variance Calculator
Welcome to the Pooled Variance Calculator! This tool helps you calculate the pooled variance from two sample data sets. It’s useful in statistics when you need to combine the variance from two different groups to perform hypothesis testing, like t-tests.
Calculate Pooled Variance
What is a Pooled Variance Calculator?
The Pooled Variance Calculator helps you determine the pooled variance when comparing two sample sets. It’s especially useful for statistical tests that assume equal variances between two groups, such as the two-sample t-test. By combining the variances from both samples, the calculator computes a weighted average of the two variances based on their sample sizes.
Formula for Pooled Variance
The formula for pooled variance is:
Pooled Variance (Sp²) = [(n1 - 1) * s1² + (n2 - 1) * s2²] / (n1 + n2 - 2)
Advantages and Disadvantages of Using the Pooled Variance Calculator
Advantages:
- Provides a quick and accurate way to calculate pooled variance.
- Helpful for hypothesis testing, especially in t-tests.
- Saves time compared to doing manual calculations.
Disadvantages:
- Assumes that the two samples come from populations with equal variances.
- Not useful for unequal sample sizes with large differences in variances.
How to Use the Pooled Variance Calculator
Simply enter the variance and sample size for two data sets (sample 1 and sample 2) in the provided fields. Click the "Calculate" button, and the pooled variance will be calculated for you.