Question 1

Which of the following is NOT a condition that must be checked before using linear regression?

Accepted Answer

Categorical Variables Condition

Question 2

Given the regression equation $$y = b_0$ + b_1$ x$$, what does the coefficient $$b_1$$ represent?

Accepted Answer

The average change in $$y$$ for a one-unit increase in $$x$$

Question 3

In the context of the Burger King menu data, the regression equation is $$	ext{Fat} = b_0$ + 0.91 	imes 	ext{Protein}. $$What is the correct interpretation of the slope?

Accepted Answer

For every additional gram of protein, there is an expected increase of 0.91 grams of fat.

Question 4

Which of the following best describes a residual in linear regression?

Accepted Answer

The difference between the observed $$y$$ and the predicted $$y$$

Question 5

Why do we square the residuals when finding the least squares regression line?

Accepted Answer

To penalize larger errors more heavily and avoid cancellation of positive and negative values

Question 6

Suppose you are analyzing the relationship between height and weight. Which variable should be the predictor (x) and which should be the response (y)?

Accepted Answer

Height as predictor (x), Weight as response (y)

Question 7

What does an $$R^2$$ value of 0.58 mean in the context of the Burger King regression model?

Accepted Answer

58% of the variation in fat content is explained by protein content

Question 8

Which of the following is a potential danger of using a regression equation to make predictions outside the range of the original data?

Accepted Answer

The predictions may be unreliable and not reflect the true relationship

Question 9

If the residual plot shows a clear pattern (e.g., a curve), what does this indicate about the linear model?

Accepted Answer

The linear model may not be appropriate; a non-linear model might fit better

Question 10

Which of the following statements about the $$p-$$value in regression analysis is correct?

Accepted Answer

A small $$p-$$value (e.g., less than 0.05) suggests the slope is statistically significant

Question 11

A regression analysis between mortgage interest rates (x) and total mortgages (y) yields $$R^2 = 0.71$. What does this mean?

Accepted Answer

71% of the variation in total mortgages is explained by interest rates

Question 12

Which of the following is NOT a correct interpretation of the y-intercept in a regression equation?

Accepted Answer

It always represents a meaningful real-world value

Question 13

Which of the following best describes the 'Does the Plot Thicken?' condition in regression?

Accepted Answer

The spread of residuals should be roughly constant across all values of x

Question 14

If the sum of the residuals from a regression line is zero, what does this indicate?

Accepted Answer

It is always true for least squares regression

Question 15

A researcher finds a statistically significant regression with $$p \u003c 0.05. $$What can they conclude?

Accepted Answer

There is evidence of a linear association between the variables

Question 16

Which of the following is a correct formula for the least squares regression line?

Accepted Answer

$$y = b_0$ + b_1$ x$$

Question 17

If the standard deviation of the residuals ($$s_e) is $$much smaller than the standard deviation of $$y$$ ($$s_y$$), what does this indicate?

Accepted Answer

The regression model explains much of the variation in $$y$$

Question 18

Which of the following scenarios would make the interpretation of the y-intercept meaningless?

Accepted Answer

Predicting average home game attendance when the number of wins is zero

Question 19

If a regression analysis yields a $$p-$$value of 0.1284 for the slope, what should you conclude at the 0.05 significance level?

Accepted Answer

There is not enough evidence to conclude a statistically significant linear relationship

Question 20

Which of the following is true about the roles of variables in regression analysis?

Accepted Answer

The explanatory variable is plotted on the x-axis and the response variable on the y-axis

Linear Regression: Concepts, Computation, and Interpretation

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드