Two Sample Z-Test Calculator

by Tutor Aspire January 17, 2023

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

301, 298, 295, 297, 304, 305, 309, 298, 291, 299, 293, 304

Sample 2

302, 309, 324, 313, 312, 310, 305, 298, 299, 300, 289, 294

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