(Solved): wpc300 Quiz #9...

WPC300 Quiz 9

Question 1

1.5 / 1.5 pts

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

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

Question 2

1.5 / 1.5 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:

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

 Question 3

1.5 / 1.5 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 money spent on repair is explained by the age of the vehicle
•    81% of money spent on repairs is explained by the age of the vehicle
•    90% of the repair cost will be 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

 Question 4

1.5 / 1.5 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 no linear relationship between profit and sales.
•    There is a negative relationship between profit and sales.
•    There is a positive relationship between profit and sales.
•    There is a linear relationship between profit and sales that can be either positive or negative.

 Question 5

1.5 / 1.5 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 dependent variable
•    a linear variable
•    a continuous variable
•    an independent variable

 Question 6

1.5 / 1.5 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:

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

 Question 7

1.5 / 1.5 pts

Which of the following is true about multi-collinearity?

•   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.
•    The effect of an independent variable on the dependent variable becomes difficult to isolate.

 Question 8

1.5 / 1.5 pts

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

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

 Question 9

1.5 / 1.5 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.
•    A unit point change in reading label will increase IQ by 5.6 point.
•   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.

 Question 10

1.5 / 1.5 pts

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

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