Question

t Test Exercise 2 refers to a t test. What is the t test? Why is the letter t used? What is unrealistic about the z test methods in Part 2 of this section?

Short answer

T-test is a statistical method to find the significant difference between the means. The letter t is used because the result is based on the t-values.

Since the population standard deviation is unknown, z-test cannot be used.

Step-by-step solution

Given information

Refer to Exercise 2 for the t-test on duration times of alcohol use for 12 different video games.

Describe t-test

T-test is a method to check the claims concerning the population mean values. The letter t is used because the test result is based on t-distribution values (test statistic follows student’s t-distribution).

Explain the use of z-test

Z-test is applied when the population is known to be normal, and the selection method is known to be random along with a known measure of population standard deviation.

It is a method used to test the claims concerning the population mean values, where the actual value of the mean is unidentified. The unrealistic part of the z-test method is that it is highly unusual to obtain the exact value of population standard deviation for such populations where the true mean is unidentified.