Exam 4: Regression Models

arrow
  • Select Tags
search iconSearch Question
flashcardsStudy Flashcards
  • Select Tags

The regression line minimizes the sum of the ________.

Free
(Essay)
4.9/5
(37)
Correct Answer:
Verified

squared errors

Both the p-value for the F-test and r2 can be interpreted the same with multiple regression models as they are with simple linear models.

Free
(True/False)
4.8/5
(42)
Correct Answer:
Verified

True

The adjusted r2 will always increase as additional variables are added to the model.

Free
(True/False)
4.7/5
(33)
Correct Answer:
Verified

False

An air conditioning and heating repair firm conducted a study to determine if the average outside temperature could be used to predict the cost of an electric bill for a home during the winter months in Richmond,VA.It was determined that a quadratic model could be used and the following prediction equation was established: Y = $1557.76 - 55.05X1 + 0.56X2 where Y = monthly cost,X1 = average temperature,and X2 = average temperature2 (a)If December has an average temperature of 43 degrees,what is the forecasted monthly electric bill? (b)If January has an average temperature of 40 degrees,what is the forecasted monthly electric bill?

(Essay)
4.7/5
(34)

The coefficient of determination resulting from a particular regression analysis was 0.85.What was the correlation coefficient,assuming a positive linear relationship?

(Multiple Choice)
4.9/5
(31)

In regression,a binary variable is also called an indicator variable.

(True/False)
4.8/5
(32)

Bob White is conducting research on monthly expenses for medical care,including over-the-counter medicine.His dependent variable is monthly expenses for medical care while his independent variable is number of family members.Below is his Excel output. Bob White is conducting research on monthly expenses for medical care,including over-the-counter medicine.His dependent variable is monthly expenses for medical care while his independent variable is number of family members.Below is his Excel output.   (a)What is the prediction equation? (b)Based on his model,each additional family member increases the predicted costs by how much? (c)Based on the significance F-test,is this model a good prediction equation? (d)What percent of the variation in medical expenses is explained by the size of the family? (e)Can the null hypothesis that the slope is zero be rejected? Why or why not? (f)What is the value of the correlation coefficient? (a)What is the prediction equation? (b)Based on his model,each additional family member increases the predicted costs by how much? (c)Based on the significance F-test,is this model a good prediction equation? (d)What percent of the variation in medical expenses is explained by the size of the family? (e)Can the null hypothesis that the slope is zero be rejected? Why or why not? (f)What is the value of the correlation coefficient?

(Essay)
4.9/5
(31)

A dummy variable is also called a(n)

(Multiple Choice)
4.9/5
(33)

The ________ measures the total variability in Y about the mean.

(Essay)
4.9/5
(37)

The coefficients of each independent variable in a multiple regression model represent slopes.

(True/False)
4.8/5
(39)

The SST measures the total variability in the dependent variable about the regression line.

(True/False)
4.7/5
(35)

An air conditioning and heating repair firm conducted a study to determine if the average outside temperature could be used to predict the cost of an electric bill for homes during the winter months in Houston,Texas.The resulting regression equation was: Y = 227.19 - 1.45X,where Y = monthly cost,X = average outside air temperature (a)If the temperature averaged 48 degrees during December,what is the forecasted cost of December's electric bill? (b)If the temperature averaged 38 degrees during January,what is the forecasted cost of January's electric bill?

(Essay)
4.9/5
(37)

Another name for the "Multiple R" that is given in Excel is ________.

(Essay)
4.9/5
(38)

One purpose of regression is to predict the value of one variable based on the other variable.

(True/False)
4.7/5
(41)

A healthcare executive is using regression to predict total revenues.She is deciding whether or not to include both patient length of stay and insurance type in her model.Her first regression model only included patient length of stay.The resulting r2 was .83,with an adjusted r2 of .82 and her level of significance was .003.In the second model,she included both patient length of stay and insurance type.The r2 was .84 and the adjusted r2 was .80 for the second model and the level of significance did not change.Which of the following statements is true?

(Multiple Choice)
4.9/5
(28)

The standard error of the estimate is also called the variance of the regression.

(True/False)
4.7/5
(29)

The errors in a regression model are assumed to have zero variance.

(True/False)
4.9/5
(36)

If every point lies on the regression line,r2 = ________.

(Essay)
4.7/5
(38)

If computing a causal linear regression model of Y = a + bX and the resultant r2 is very near zero,then one would be able to conclude that

(Multiple Choice)
4.9/5
(32)

Bob White is conducting research on monthly expenses for medical care,including over the counter medicine.His dependent variable is monthly expenses for medical care while his independent variables are number of family members and insurance type (government funded,private insurance and other).He has coded insurance type as the following: X2 = 1 if government funded,X3 = 1 if private insurance Below is his Excel output. Bob White is conducting research on monthly expenses for medical care,including over the counter medicine.His dependent variable is monthly expenses for medical care while his independent variables are number of family members and insurance type (government funded,private insurance and other).He has coded insurance type as the following: X<sub>2</sub> = 1 if government funded,X<sub>3</sub> = 1 if private insurance Below is his Excel output.   (a)What is the prediction equation? (b)Based on the significance F-test,is this model a good prediction equation? (c)What percent of the variation in medical expenses is explained by the independent variables? (d)Based on his model,what are the predicted monthly expenses for a family of four with private insurance? (e)Based on his model,what are the predicted monthly expenses for a family of two with government funded insurance? (f)Based on his model,what are the predicted monthly expenses for a family of five with no insurance? (a)What is the prediction equation? (b)Based on the significance F-test,is this model a good prediction equation? (c)What percent of the variation in medical expenses is explained by the independent variables? (d)Based on his model,what are the predicted monthly expenses for a family of four with private insurance? (e)Based on his model,what are the predicted monthly expenses for a family of two with government funded insurance? (f)Based on his model,what are the predicted monthly expenses for a family of five with no insurance?

(Essay)
4.8/5
(31)
Showing 1 - 20 of 133
close modal

Filters

  • Essay(0)
  • Multiple Choice(0)
  • Short Answer(0)
  • True False(0)
  • Matching(0)