Introduction to Inference: Pre test

Which of the following best describes a Type I error?

• The null is true, but we mistakenly reject it.

• The null is false and we reject it.

• The null is false, but we fail to reject it.

• The null is true but we fail to reject it.

• The null is true, and we fail to reject it.

The null hypothesis is represented by:

• Ha

• Ho

• t*

• HP

• μ

What is the Power of a test?

• A strong force
• The probability that we correctly reject a false null.
• The probability that we correctly accept a true null.
• How tough it is.

Which of the following best describes a type II error?

• The null is true, but we mistakenly reject it.

• The null is false and we reject it.

• The null is false, but we fail to reject it.

• The null is true but we fail to reject it.

• Te null is false, and we reject it.

What does it mean when a test is statistically significant?

• it has reached alpha level status
• the test statistic had a P-value higher than the alpha level
• the test statistic had a P-value lower than the alpha level
• it is important in practical terms

How can you reduce both Type I and Type II errors?

• it can't be reduced
• redo the tests
• increase the sample size
• tamper with the data

What is another name for a type I error?

• false negative

• false positive

• true negative

• true positive

Which of the following is tested for significance?

• Null hypothesis

• Alternative hypothesis

• Alpha level

• Statistical power

Which of the following is NOT a measure used in inferential statistics?

• z score

• t test

• z test

• Student's test

Suppose the P-value for a hypothesis test is 0.0304.  Using a = 0.05, what is the appropriate conclusion?

•   a)  reject the null
• b)  reject the alternative
• c)  Accept the null
• d)  Fail to reject the alternative