Question

Chapter 4, Section 4, Exercise 139-143

Type I and Type II Errors

In the situation below, describe what it means in that context to make a Type I and Type II error.
Testing to see whether taking a vitamin supplement each day has significant health benefits. There are no (known) harmful side effects of the supplement.

Making a Type I error means:

People should not take any kind of vitamin supplements.

Fail to detect that the supplements are beneficial, when they actually are.

There is evidence that the supplements are beneficial.

There is not enough evidence that the supplements are beneficial.

Conclude people should take the vitamin supplements when they actually don`t help.

People should take any kind of vitamin supplements.

Making a Type II error means:

Fail to detect that the supplements are beneficial, when they actually are.

There is evidence that the supplements are beneficial.

People should take any kind of vitamin supplements.

There is not enough evidence that the supplements are beneficial.

Conclude people should take the vitamin supplements when they actually don`t help.

People should not take any kind of vitamin supplements.

Answer 1

Type I error occurs when one reject null hypothesis even when it is true.

In this case, null hypothesis is that there is no health benefits of taking a vitamin supplement

So, type I error will be concluding that there are health benefits of taking a vitamin supplement, even when actually there are no health benefits.

Correct Answer:

Making a Type I error means: Conclude people should take the vitamin supplements when they actually don`t help.

Type II error occurs when one fail to reject null hypothesis, even when it is false.

In this case, null hypothesis is that there is no health benefits of taking a vitamin supplement

So, type II error will be concluding that there no health benefits of taking a vitamin supplement, even when actually there are health benefits.

Correct Answer:

Making a Type II error means: Fail to detect that the supplements are beneficial, when they actually are.