# (Solved): WPC 300 Quiz 5 2020 ...

**WPC 300 Quiz 5 2020**

**Score for this attempt: 20 out of 20**

**Question 1**

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 exam is a poor predictor of success.
- 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.

**Question 2**

You need to find out which customer is likely to buy your product. A sample data is available from your current customer base. Which of the following analysis method will be appropriate for this study?

- Multiple linear regression
- Logistic regression
- Linear regression
- Clustering

**Question 3**

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

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

**Question 4**

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, the predicted cost of the car is:

- $6900
- $2090
- $7400
- $3850

**Question 5**

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 5.6 point increase in reading label
- 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 reading label will increase IQ by 5.6 point

**Question 6**

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

- Presence of multi-collinearity effect
- Relationship between dependent and independent variables should be linear
- Residuals are normally distributed
- No correlations between the independent variables

**Question 7**

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

- Residual variance
- Regression variance
- Predicted variance
- Total variance

**Question 8**

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

- 90% of the repair cost will be explained by the age of an auto
- 90% of the money spent on repair is explained by the age of an auto
- 81% of money spent on repairs is explained by the age of an auto
- 81% of the variation in the money spent on repairs is explained by the age of the auto

Feedback: R=0.9, R-squared = 0.81. Remember the definition of R-squared.

**Question 9**

Which of the following is true about multi-collinearity?

- The effect of a dependent variable on another becomes difficult to isolate.
- Is measured using the statistical variance inflation factor (VIF)
- P-value reduces significantly leading to rejection of the null hypothesis.
- Regression coefficients become clearer and are easier to interpret

**Question 10**

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 continuous variable
- An independent variable
- A qualitative variable