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DS 101 Version R082–Sample Exam Questions

Simple Linear Regression Questions

1.In regression analysis, the model in the form is called

a. / regression equation
b. / correlation equation
c. / estimated regression equation
d. / regression model

2.The mathematical equation relating the independent variable to the expected value of the dependent variable; that is, E(y) = 0 + 1x, is known as

a. / regression equation
b. / correlation equation
c. / estimated regression equation
d. / regression model

3.The model developed from sample data that has the form of is known as

a. / regression equation
b. / correlation equation
c. / estimated regression equation
d. / regression model

4.In regression analysis, the unbiased estimate of the variance is

a. / coefficient of correlation
b. / coefficient of determination
c. / mean square error
d. / slope of the regression equation

5.The interval estimate of the mean value of y for a given value of x is

a. / prediction interval estimate
b. / confidence interval estimate
c. / average regression
d. / x versus y correlation interval

6.The standard error is the

a. / t-statistic squared
b. / square root of SSE
c. / square root of SST
d. / square root of MSE

7.If MSE is known, you can compute the

a. / r square
b. / coefficient of determination
c. / standard error
d. / all of these alternatives are correct

8.In regression analysis, which of the following is not a required assumption about the error term ?

a. / The expected value of the error term is one.
b. / The variance of the error term is the same for all values of X.
c. / The values of the error term are independent.
d. / The error term is normally distributed.

9.Larger values of r2 imply that the observations are more closely grouped about the

a. / average value of the independent variables
b. / average value of the dependent variable
c. / least squares line
d. / origin

10.In a regression and correlation analysis if r2 = 1, then

a. / SSE must also be equal to one
b. / SSE must be equal to zero
c. / SSE can be any positive value
d. / SSE must be negative

11.In a regression and correlation analysis if r2 = 1, then

a. / SSE = SST
b. / SSE = 1
c. / SSR = SSE
d. / SSR = SST

12.The coefficient of correlation

a. / is the square of the coefficient of determination
b. / is the square root of the coefficient of determination
c. / is the same as r-square
d. / can never be negative

13.In regression analysis, if the independent variable is measured in pounds, the dependent variable

a. / must also be in pounds
b. / must be in some unit of weight
c. / cannot be in pounds
d. / can be any units

14.A regression analysis between sales (in $1000) and price (in dollars) resulted in the following equation

= 50,000 - 8X

The above equation implies that an

a. / increase of $1 in price is associated with a decrease of $8 in sales
b. / increase of $8 in price is associated with an increase of $8,000 in sales
c. / increase of $1 in price is associated with a decrease of $42,000 in sales
d. / increase of $1 in price is associated with a decrease of $8000 in sales

15.Regression analysis was applied between sales (in $1000) and advertising (in $100) and the following regression function was obtained.

= 500 + 4 X

Based on the above estimated regression line if advertising is $10,000, then the point estimate for sales (in dollars) is

a. / $900
b. / $900,000
c. / $40,500
d. / $505,000

Multiple Regression Questions

1.The mathematical equation relating the expected value of the dependent variable to the value of the independent variables, which has the form of E(y) = is

a. / a simple linear regression model
b. / a multiple nonlinear regression model
c. / an estimated multiple regression equation
d. / a multiple regression equation

2.The estimate of the multiple regression equation based on the sample data, which has the form of E(y) =

a. / a simple linear regression model
b. / a multiple nonlinear regression model
c. / an estimated multiple regression equation
d. / a multiple regression equation

3.The mathematical equation that explains how the dependent variable y is related to several independent variables x1, x2, ..., xp and the error term  is

a. / a simple nonlinear regression model
b. / a multiple regression model
c. / an estimated multiple regression equation
d. / a multiple regression equation

4.A measure of the effect of an unusual x value on the regression results is called

a. / Cook’s D
b. / Leverage
c. / odd ratio
d. / unusual regression

5.In a multiple regression model, the error term  is assumed to be a random variable with a mean of

a. / zero
b. / -1
c. / 1
d. / any value

6.A regression model in which more than one independent variable is used to predict the dependent variable is called

a. / a simple linear regression model
b. / a multiple regression model
c. / an independent model
d. / None of these alternatives is correct.

7.A multiple regression model has the form

As x1 increases by 1 unit (holding x2 constant), y is expected to

a. / increase by 9 units
b. / decrease by 9 units
c. / increase by 2 units
d. / decrease by 2 units

8.A multiple regression model has the form

As X increases by 1 unit (holding W constant), Y is expected to

a. / increase by 11 units
b. / decrease by 11 units
c. / increase by 6 units
d. / decrease by 6 units

Exhibit 15-2

A regression model between sales (Y in $1,000), unit price (X1 in dollars) and television advertisement (X2 in dollars) resulted in the following function:

For this model SSR = 3500, SSE = 1500, and the sample size is 18.

9.Refer to Exhibit 15-2. The coefficient of the unit price indicates that if the unit price is

a. / increased by $1 (holding advertising constant), sales are expected to increase by $3
b. / decreased by $1 (holding advertising constant), sales are expected to decrease by $3
c. / increased by $1 (holding advertising constant), sales are expected to increase by $4,000
d. / increased by $1 (holding advertising constant), sales are expected to decrease by $3,000

10.Refer to Exhibit 15-2. The coefficient of X2 indicates that if television advertising is increased by $1 (holding the unit price constant), sales are expected to

a. / increase by $5
b. / increase by $12,000
c. / increase by $5,000
d. / decrease by $2,000

Exhibit 15-4

a.

b.

c.

d.

11.Which equation describes the multiple regression model?

a. / Equation A
b. / Equation B
c. / Equation C
d. / Equation D

12.Which equation gives the estimated regression line?

a. / Equation A
b. / Equation B
c. / Equation C
d. / Equation D

13.Which equation describes the multiple regression equation?

a. / Equation A
b. / Equation B
c. / Equation C
d. / Equation D

Exhibit 15-5

Below you are given a partial Minitab output based on a sample of 25 observations.

Coefficient / Standard Error
Constant / 145.321 / 48.682
X1 / 25.625 / 9.150
X2 / -5.720 / 3.575
X3 / 0.823 / 0.183

14.Refer to Exhibit 15-5. The estimated regression equation is

a. /
b. /
c. /
d. /

15.Refer to Exhibit 15-5. The interpretation of the coefficient on X1 is that

a. / a one unit change in X1 will lead to a 25.625 unit change in Y
b. / a one unit change in X1 will lead to a 25.625 unit increase in Y when all other variables are held constant
c. / a one unit change in X1 will lead to a 25.625 unit increase in X2 when all other variables are held constant
d. / It is impossible to interpret the coefficient.