John rejected his null hypothesis in a righttailed test for

John rejected his null hypothesis in a right-tailed test for a mean at = .025 because his critical t value was 2.000 and his calculated t value was 2.345. We can be sure that:

John committed both Type I and Type II error.

John committed neither Type I nor Type II error.

John did not commit Type I error.

John did not commit Type II error.

Solution

A type I error can only occur when you rejected the null hypothesis.

A type II error can only occur when you did not reject the null hypothesis.

Thus, here,

OPTION D: John did not commit Type II error. [answer, D]