Unit 3

Question 1

Measures an outcome of a study

Answer 1

Response Variable

Question 2

May help predict or explain changes in a response variable

Answer 2

Explanatory Variable

Question 3

Shows the relationship between two quantitative variables measured on the same individuals.

Answer 3

Scatterplot

Question 4

Values of one variable tend to increase as the values of the other variable increase

Answer 4

Positive Association

Question 5

Values of one variable tend to decrease as the values of the other variable increase

Answer 5

Negative Association

Question 6

Knowing the value of one variable does not help us predict the value of the other variable

Answer 6

No Association

Question 7

Measures the direction and strength of an association

Answer 7

Correlation r

Question 8

A line that models how a response variable y changes as an explanatory variable x changes

Answer 8

Regression

Line

Question 9

The use of a regression line for prediction outside the interval of x values used to obtain the line

Answer 9

Extrapolation

Question 10

The difference between the actual value of y and the value of y predicted by the regression line

Answer 10

Residual

Question 11

The predicted value of y when x = 0

Answer 11

y intercept

Question 12

The amount by which the predicted value of y changes when x increases by 1 unit

Answer 12

Slope

Question 13

The line that makes the sum of the squared residuals as small as possible

Answer 13

Least-squares Regression Line

Question 14

A scatterplot that displays the residuals on the vertical axis and the explanatory variable on the horizontal axis

Answer 14

Residual Plot

Question 15

Measures the size of a typical residual

Answer 15

Standard Deviation of Residuals s

Question 16

Measures the percent reduction in the sum of squared residuals when using the least-squares regression line to make predictions, rather than the mean value of y

Answer 16

The coefficient of determination r^2

Question 17

Have much larger or much smaller x values than the other points in the data set

Answer 17

High Leverage

Question 18

A point that does not follow the pattern of the data and has a large residual

Answer 18

Outlier

Question 19

Any point that, if removed, substantially changes the slope, y intercept, correlation, coefficient of determination, or standard deviation of the residuals

Answer 19

Influential Point