Correlation and Regression

Question 1

Extrapolation

Answer 1

use of regression line for predictions far outside of the range of values of the variable x

Question 2

Residual

Answer 2

difference between an observed value of the response variable and the value predicted by the regression line

observed - predicted

Question 3

What makes an observation influential?

Answer 3

If its removal would drastically change results of the calculation

Question 4

_______ are often influential.

Answer 4

Outliers

Question 5

Lurking Variable

Answer 5

Outside of x and y but can influence interpretation of these variables and their relationships

Question 6

T or F
Association implies causation.

Answer 6

False, correlation is not enough evidence

Question 7

Restricted-range problem

Answer 7

This occurs when the range of values measured for one of the variables is restricted for some reason.

Question 8

T or F

A correlation based on averages is usually higher than if we used data for individuals.

Answer 8

True

Question 9

How do you compare two categorical variables?

Answer 9

Contingency tables
Bar plots

Question 10

How do you compare one continuous and one categorical variable?

Answer 10

Side-by-side boxplots
Bar plots for means

Question 11

How do you compare two continuous variables?

Answer 11

Scatterplots