# Type I and Type II Errors

Not what you're looking for?

In the last few years, an organization has conducted 200 clinical trials to test the effectiveness of anti-anxiety drugs. Suppose, however, that all of those drugs were obtained from the same fraudulent supplier, which was later revealed to have been sending only inert substances (e.g., distilled water, sugar pills) instead of real drugs. If alpha = .05 was used for all hypothesis tests, how many of these 200 experiments would you expect to yield significant results? How many Type I errors would you expect? How many Type II errors would you expect?

##### Purchase this Solution

##### Solution Summary

Type I and type II errors are examined in 200 clinical trials to test the effectiveness of anti-anxiety drugs.

##### Solution Preview

In each of the 200 trials, the null and alternative hypotheses are:

H0: The drug is not effective

HA: The drug is effective

And we learned later that the true state of nature was H0: the drug is not effective.

When we set up a hypothesis test we choose the level of significance, ...

##### Purchase this Solution

##### Free BrainMass Quizzes

##### Measures of Central Tendency

This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.

##### Measures of Central Tendency

Tests knowledge of the three main measures of central tendency, including some simple calculation questions.

##### Know Your Statistical Concepts

Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.

##### Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.