Which of the following statements is true of a null hypothesis?

A) The population means are not equal.
B) The difference in means is not due to random error.
C) The mean of the experimental group is not equal to the mean of the control group.
D) The mean of the placebo treatment is equal to the mean of the experimental treatment group.

Null Hypothesis

The hypothesis, used for statistical purposes, that the variables under investigation are not related in the population, that any observed effect based on sample results is due to random error.

Experimental Group

This is the group in an experiment that receives the variable being tested.

Control Group

In an experiment, the group that does not receive the treatment being tested, used as a benchmark to measure how the other tested subjects do.