(Solved): Wpc300 Quiz 5: Regression ...

Wpc300

Quiz 5: Regression 

The score for this quiz: 10 out of 10

Question 1

1 / 1 pts

What would be the null hypothesis for testing a linear regression model with profit as the dependent variable and sales as the independent variable?

•   There is a negative relationship between profit and sales. 
•   There is a linear relationship between profit and sales that can be either positive or negative. 
•   There is no linear relationship between profit and sales. 
•   There is a positive relationship between profit and sales. 

Question 2

1 / 1 pts

A market analyst is developing a regression model to predict monthly household expenditures on groceries as a function of family size, household income, and household neighborhood (urban, suburban, and rural). The "neighborhood" variable in this model is ________.

•   a linear variable 
•   an independent variable 
•   a continuous variable 
•   a dependent variable

 Question 3

1 / 1 pts

Which of the following statement is true based on the following regression equation?
IQ = 4.0 + Reading Label * 5.6

•   A unit point change in IQ will result in 9.6-point increase in reading label. 
•   Reading label is not a good predictor of IQ.
•   A unit point change in IQ will result in 5.6-point increase in reading label.
•   A unit point change in reading label will increase IQ by 5.6 point. 

Question 4

1 / 1 pts

The value of R-Squared always falls between ________ and ________, inclusive.

•   -infinity to + infinity 
•   0 and 1
•   -1 and +1 
•   0 and -1

Question 5

1 / 1 pts

The correlation coefficient between the age of a vehicle and the money spent to repair it is 0.9. Which of the following statement is true?

•   90% of the repair cost will be explained by the age of the vehicle 
•   90% of the money spent on repair is explained by the age of the vehicle 
•   81% of the variation in the money spent on repairs is explained by the age of the vehicle
•   81% of money spent on repairs is explained by the age of the vehicle 

Question 6

1 / 1 pts

Which of the following is true about multi-collinearity?

•   The effect of an independent variable on the dependent variable becomes easy to isolate.
•    The regression coefficients become clearer and are easier to interpret.
•   It is measured using a measure called variance inflation factor (VIF). 
•   The P-value reduces significantly, leading to rejection of the null hypothesis. 

Question 7

1 / 1 pts

The unexplained variance in the regression analysis is also known as:

•   Total variance
•   Residual variance 
•   Predicted variance 
•   Regression variance 

Question 8

1 / 1 pts

A correlation coefficient between “college entrance exam” grades and scholastic achievement was found to be -1.08. On the basis of this, you would tell the university that:

•   The entrance exam is a good predictor of success. 
•   They should hire a new statistician. 
•   The exam is a poor predictor of success.
•   Students who do best on this exam will make the worst students.

Question 9

1 / 1 pts

A manager wishes to predict the annual cost (y) of an automobile based on the number of miles (x) driven. The following model was developed: y = $1500 + 0.36x. If a car is driven 15000 miles in a year, the model predicts the annual cost of the car to be:

•   $7400 
•   $3850 
•   $2090 
•   $6900

Question 10

1 / 1 pts

Which of the following assumptions is not true for multiple linear regression?

•   The independent variables are not correlated. 
•   The relationship between dependent and independent variables is linear. 
•   There will be a multi-collinearity effect. 
•   The residuals are normally distributed.