AP Statistics Phrases to Know

Chi Sqaured GOF and Homogeneity Assumptions and Conditions

Counts (categorical)

Randomization (SRS or Random Assignment)

Pop > 10n (for sample)

These two combine to satisfy the independence requirement (use context)

Expected counts > 5

Chi Sqaured Independence Assumptions and Conditions

Counts (categorical)

Randomization (SRS or Random Assignment)

Pop > 10n (for sample)

These two combine to satisfy the independence requirement (use context)

Expected counts > 5

LinReg T-Test/ Interval Assumptions and Conditions

Linear scatterplot (show scatter plot)

Independent (errors)

Normal Histogram (show histogram)

Equal Variances (show residuals plot)

Randomization

Chi Squared Independent Hypotheses

Ho: The variables are independent of each other

Ha: The variables are not independent of each other

Chi Squared Homogeneity Hypotheses

Ho: The distribution is the same for all populations

Ha: The distribution is not the same for all populations

Chi Squared GOF Hypotheses

Ho: The distribution look a certain way (based on given info)

Ha: The distribution looks different from what was hypothesized

LinReg T-Test Hypotheses

Ho: B=0 The relationship is not linear

Ha: B≠,>,< The relationship is linear

What are unbiased estimators of ⲁ and B

a and b

What are the unbiased estimators of M, 𝜎, and p

Sx, p(hat), and mean

When are standardized Residuals used?

If null hypotheses is rejected to determine which population was most different from the others

What makes homogeneity tests different from Independence tests

Homogeneity tests have groups that are sampled in different groups separately

What makes independence tests different from homogeneity tests?

Independence tests sample people and then split them into groups

What is the purpose of a LinReg test?

Determining if there is a linear association between the two variables

P-value in LinReg Tests

P-value is two-tailed, but to get one-tailed p-value, divide by two

LinReg T-interval Conclusion

I am % confident that the true slope of the regression line…is between…

What is the purpose of ^_X2 Test for Independence

It is used to determine an association between two categorical variables from one population

df equation for x² tests

df = # of categories - 1

(row -1) (column-1)