A type II error occurs when: a. the null hypothesis is incorrectly rejected when it is true b. the sample mean differs from the population mean c. the test is biased d. the null hypothesis is incorrectly accepted when it is false

d. the null hypothesis is incorrectly accepted when it is false

Explanation:

Null Hypothesis is an important aspect of hypothesis testing, stating no difference i. e neutrality & no relationship between the variables. It is denoted by H0

Example : Analysing relationship between variable X & variable Y;

Null Hypothesis : There is no relationship between X & Y.

Type 2 Error is accepting the null hypothesis when it is actually false. It means accepting that there is no relationship between X & Y, when they are actually related.