chapter 5

Question 1

What is a regression line?

Answer 1

is a straight line that describes how a response variable y changes as an explanatory variable x changes. We often use a regression line to predict the value of x for a given value of x when we believe the relationship between y and
x is linear.

Question 2

What is fact 1 when regarding least squares regression line?

Answer 2

The distinction between explanatory and response variables is essential in regression

Question 3

What is fact 2 when regarding least squares regression line?

Answer 3

There is a close connection between correlation and the slope of the least-squares line

Question 4

What is a residual?

Answer 4

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

Question 5

When is a observation influential?

Answer 5

An observation is influential for a statistical calculation if removing it would markedly change the result of the calculation

Question 6

What is ecological correlation?

Answer 6

A correlation based on averages rather than on individuals is called an ecological correlation