A two sample z-test is used to test whether or not the means of two populations are equal when the population standard deviations are known.

To perform a two sample z-test, simply fill in the information below and then click the “Calculate” button.

Enter raw data Enter summary data

Sample 1

Sample 2

x₁ (sample 1 mean)

n₁ (sample 1 size)

x₂ (sample 2 mean)

n₂ (sample 2 size)

σ₁ (population 1 standard deviation)

σ₂ (population 2 standard deviation)

z = -1.608761

p-value (one-tailed) = 0.060963

p-value (two-tailed) = 0.121926