Statistics and Probability

Chapter 13 Outline

Chapter 13

Main Topics

13.1 Test for Goodness of Fit

A. Chi-Squared Distribution

1. The Chi-Squared Distribution is skewed right.

2. Must use Degree’s of Freedom

3. As the sample size increases, the curve

B. The test is to verify whether or not a distribution

of a population is the same as the hypothesized

amounts.

1. The Null Hypothesis

a. The actual proportions is equal to the

hypothesized proportions

2. Alternative Hypothesis

a. The actual proportions is different from the

hypothesized proportions

3. Equation

a. (see Chi-Squared Eqn)

4. Conditions

a. All expected counts are at least 1 or above

b. No more than 20% of the expected counts

are less than five

13.2 Inference for Two-Way Tables

A. Two-Way Tables

1. Dimensions are r x c (row and column)

2. Expected counts are calculated by product of

row total and column total divided by the entire

total.

3. Use the same equation as Test for Goodness of

Fit.

4. Degree of Freedom is calculated by (r-1)(c-1).

B. Test for Homogeneity of Populations

1. Test is reveal if the proportions for each group

are the same.

C. Test for Independence.

1. Same test as Homogeneity, but the result is to

determine if one category influences another

category.

AP Statistics

Syllabus

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