Margin of Error Calculator

Find the margin of error for a mean.

Margin of error 2.94

Formula: MOE = z × σ ÷ √n

Step-by-step with your numbers:

1. Values used:

2. Standard deviation = 15

3. Sample size = 100

4. Confidence level = 1.96

6. Margin of error = 2.94

Did we solve your problem today?

The margin of error is the ± range around a sample estimate.

The math behind it

MOE = z × standard deviation ÷ √(sample size). Bigger samples shrink the margin.

σ 15, n 100, 95% → ±2.94.

Reduce it?

Increase the sample size (it scales with 1/√n).