Statistics
Pooled Variance - Statistics
Learn the pooled variance with examples, step-by-step guide, and calculator tools. Combined variance from two samples
The pooled variance is a fundamental concept in statistics. Combined variance from two samples. This page provides a comprehensive guide with worked examples and practical applications.
The Formula
\[s_p^2 = \frac{(n_1-1)s_1^2 + (n_2-1)s_2^2}{n_1 + n_2 - 2}\]
Variables
sp²
Pooled variance
n₁, n₂
Sample sizes
s₁², s₂²
Sample variances
Step-by-Step Guide
- 1
Step 1: Gather your data values
- 2
Step 2: Apply the formula
- 3
Step 3: Perform the calculations
- 4
Step 4: Interpret the result
Examples
Example 1
Example 1: [] → sp² = (9×16 + 9×25) / 18 = 369/18 = 20.5
Example 2
Example 2: 20.5
Frequently Asked Questions
What is the pooled variance?
Combined variance from two samples
How do I calculate pooled variance?
Use the formula: s_p^2 = \frac{(n_1-1)s_1^2 + (n_2-1)s_2^2}{n_1 + n_2 - 2}. Follow the steps provided above.
What tools can help with pooled variance?
We provide online calculators: statistics-calculator