AP Statistics Chapter 12 Review

What does a low chi-square indicate?

The sample meets expectations.

What does a high chi-square indicate?

The sample does not meet expectations.

How do you find the p-value GIVEN the chi-square value?

You plug in the chi-square value as the lower boundary and, depending on your hypothesis, double it.

How do you know when to test for homogeneity?

When there are at least two samples and one variable is recorded.

How do you know when to test for independence?

When there is one sample with two/multiple variables being recorded.

What does chi-square measure?

How much the observed counts deviate from the expected counts.

What happens if you have a large chi-square value? Is this evidence against the H_O?

Yes

How do you calculate the degrees of freedom for two-way tables?

You do number of columns-1 times the number of rows-1

How do you write a null hypothesis for Chi-Square test for Homogeneity?

There is no difference in the distribution of _____ for several populations/treatments

How do you write a null hypothesis for a Chi-Square test for Independence?

Ho: There is no association between (categorical 1) and (categorical variable 2)

What does independent mean?

no association

How do you find expected counts for two way tables?

(Row Total * Column Total)/Table Total

DO THIS FOR THE SMALLEST VALUES

How do you know when to use chi-square versus T-test/z-tests?

Because chi-square is for categorical variables while T and Z are for quantitative.

What do you have to say in the Plan step?

You need to say your test type “EX: chi-square goodness of fit, chi-square test for independence”

What is the general equation for a population regression line?

U_Y = a+Bx

How do you calculate the degrees of freedom for t-interval for slope?

df=n-2

When you’re doing a t-test for slope, what is your Null hypothesis?

H_o: B = B_o

True slope = Claimed Slope

How do you find the p-value given the test statistic in a t-test for slope?

tCDF where df is n-2

What is the USUALLY the alternate hypothesis in t-test for slope?

H_A: B≠0

What is the calculator test for t-test for slope called?

Linear Regression t-test.

How do you calculate the degrees of freedom for a chi-square goodness of fit test?

df = n-1

What is the null/alternative hypothesis for a chi-square goodness of fit test?

H_O: The stated distribution of _______ is correct
H_A: The stated distribution is not correct