8.1 Review

Understanding Null and Alternative Hypothesis

100

What is a statement about a PROPERTY of a population?

What is it called when we test this?

Hypothesis; Hypothesis Test

200

H₀ is the ... and means ... ?

H₁ is the ... and means ...?

H₀ = Null Hypothesis; Not guilty or Nothing Has Changed

H₁ = Alternative Hypothesis; Guilty, Something Has Changed

300

The null hypothesis will always be the parameter being measured is WHAT to the claimed value (greater than, less than, equal to) ?

Equal to

400

What are the three different types of alternative hypothesis?

1. Not Equal To (2 Tail Test)

2. Greater Than (Right Tail Test)

3. Less Than (Left Tail Test)

500

For which hypothesis do you support the claim? For which do you reject?

Alternative Hypothesis = Support

Null Hypothesis = Reject

Understanding Statistical Tests and Errors

100

What test uses data obtained from a sample to decide whether the null hypothesis should be rejected?

Statistical Test

200

How many possible outcomes are there in a hypothesis test?

4

300

If you do not reject the null hypothesis when it was false, this is called a ...?

Type II Error

400

If you reject the null hypothesis when it was true, this is called a ...?

Type I Error

500

Beta (B) represents which error, Type I or Type II error?

Type II Error

Significance Levels

100

If the significance level is .10, this means ...?

There is a 10% chance of rejecting the true hypothesis

200

What are the three most common significance levels?

.10, .05, .01

300

Find the critical value(s) to use in a left-tailed test if the significance level is .05. 

-1.64

400

Find the critical value(s) of a right-tailed test with a significance level of .01. 

2.33

500

Find the critical value(s) of a two-tailed test with a significance level of .10.

-1.65, 1.65

Miscellaneous

100

Are statistical decisions proof? Why or why not?

No, because the only way to PROVE something would be to use the ENTIRE population which is impractical and rather impossible to do.

200

If a significance level is not given, which should you use?

.05

300

Do you ever show that the null hypothesis is true?

No, you just REJECT the claim that it is not true

400

A research hypothesis is the same as ...?

Alternative Hypothesis

500

What statement would you use if you are rejecting H₀ when the claim is H₁?

There IS enough statistical evidence to SUPPORT the claim

Problems

100

State the null and alternative hypotheses.

1. Average amount of candy consumed by Americans per year is more than 23.9 pounds.

H₀: u = 23.9

H₁: u > 23.9

200

State the null and alternative hypotheses.

The average number of dogs a family owns is 1.6.

H₀: u = 1.6

H₁: u does not equal 1.6

300

State the null and alternative hypotheses. 

Less than 60% of books sold in a book store are hardback books.

H₀: p = .60

H₁: p < .60

400

State the null and alternative hypotheses.

Eighty-five percent of people arrested for gambling are men.

H₀: p=.85

H₁: p does not equal .85

500

Is the critical value greater for a right-tailed test of .05 or a left-tailed of .01?

Right-Tailed Test, as its critical value is 1.65 while left-tailed test is -2.33