Practice Questions 9.4

In regression, if a residual tells how close a single point is to a line, can the sum of all residuals be used to find the actual regression line

A)  No, because the sum of all residuals always equals zero.
B) No, because the concept of a residual applies to only one point.
C) No, because the sum of all residuals might equal zero.
D) Yes, because regression line is found when the sum of all residuals equals zero.

In regression, what do the terms Least Squares mean

A) Least, means the smallest residual of all the points.
B) Squares, means all the sum of all the residuals has been squared.
C) Least, means the smallest value for the sum.
D) Squares, means all the residuals have been squared.

In regression, which of the following choices is true when the regression line is found?

A) Each and every residual equals zero.
B) The sum of the squared residuals equals zero.
C) The sum of the residuals equals zero.
D) The sum of the squared residuals has the smallest value possible.

In regression, given the descriptive statistics below for two dependent variables, what is the value of the sample slope / the sample y-intercept of the regression line?

A) Sample slope = 108.2 / sample y-intercept = 1,140.4
B) Sample slope = 12.8 / sample y-intercept = 4.4
C) Sample slope = -12.8 / sample y-intercept = 311.6
D)  Sample slope = 12.7 / sample y-intercept = 6.0

In regression, given the descriptive statistics below for the variables Outside Temperature (degree F) and Air Conditioning Cost (dollars), what is the expected change in AC Cost for a 1-degree F increase in Outside Temp?

Variable	x̄	s	r
Outside Temp	12	6
AC Cost	158	80	0.95

A)  AC cost goes up 12.7 dollars.
B) AC cost goes up 78 dollars.
C) AC cost goes up 1.27 dollars.
D) AC cost goes up 80 dollars.

In regression, given the descriptive statistics below for the variables Outside Temperature (degree F) and Air Conditioning Cost (dollars), what is the expected AC Cost for an 80-degree F Outside Temp?

Variable	x̄	s	r
Outside Temp	12	6
AC Cost	158	80	0.95

A) Expected AC cost is 1,010 dollars.
B) Expected AC cost is 158 dollars.
C)  Expected AC cost is 1,022 dollars.
D) Expected AC cost is 238 dollars.

In regression, given the descriptive statistics below for two dependent variables, what is the value of the sample slope / the sample y-intercept of the regression line?

Variable	x̄	s	r
Predictor	64	6.4
Response	28	6.6	0.57

A)  Sample slope= 0.6 / sample y-intercept= -9.6
B) Sample slope= 32.8 / sample y-intercept= 12.2
C) Sample slope= 12.2 / sample y-intercept= 32.8
D) Sample slope= -9.6 / sample y-intercept= 0.6

In regression, given the descriptive statistics below for the variables Calories eaten (cal) and body Weight (grams) of white mice, what is the expected change in Weight for a 10 Calorie decrease in diet?

Variable	x̄	s	r
Calories	64	6.4
Weight	28	6.6	0.57

A) Body Weight goes up 6.6 grams.
B) Body Weight goes down 12.2 grams.
C)  Body Weight goes down 6 grams.
D) Body Weight goes down 6.6 grams.

In regression, given the descriptive statistics below for the variables Calories eaten (cal) and body Weight (grams) of white mice, what is the expected Weight for a diet of 100 Calories?

Variable	x̄	s	r
Calories	64	6.4
Weight	28	6.6	0.57

A) An expected body Weight of 43.7 grams.
B)  An expected body Weight of 50.4 grams.
C) An expected body Weight of 69.6 grams.
D) An expected body Weight of 33.7 grams.

Using the linear regression information below relating the size of a diamond (Carats) with its Price (dollars) , match each statement with its appropriate value.

A) The change in Price for a one Carat size increase (use sample information).
B) Expected price for a four (4) carat diamond (use sample information).
C) The appropriate value for the population slope (use population information).

Using the linear regression information below relating the size of a female's brain (MRI Count) with her Intelligence Quotient (IQ) , match each statement with its appropriate value.

A. The change in IQ for a 100 MRI count increase (use sample information).
B. Expected IQ of a female with a MRI count of 900 (use sample information). 
C. The appropriate value for the population slope (use population information).

__ Go up 1.7 IQ units
__ 134.7 IQ units
__ 0 IQ units/ MRI count

Using the linear regression information below relating the batting average (Average) of a baseball team with the number of home runs scored in a season (Home_Runs), match each statement with its appropriate value.


A. The change in home runs for a 0.01 batting average increase (use sample information).
B. Expected number of home runs with a batting average of 0.263 (use sample information).
C. The appropriate value for the population slope (use population information).