WOLFRAM|DEMONSTRATIONS PROJECT

Power Analysis for a Two-Sample t-Test

​
effect size
0.4
sample size
30
p-value
0.05
power: 32%
A
t
-test examines a statistical hypothesis following a Student
t
distribution under the null hypothesis. The object is to estimate the mean of a normal distribution for small sample size and unknown standard deviation. The
t
-test can be used to determine if two sets of data are significantly different from one other. This Demonstration provides a visual representation for calculating power in a two-sample
t
-test. Use the sliders to manipulate effect size, sample size and the
p
-value to see how they affect the power in hypothesis testing. The area of the blue shaded region represents the power.