answers 2025/2026 latest update
Which of the following corresponds to the explained part of the variation in the dependent
variable?
a. The total sum of squares
b. The regression sum of squares
c. The residual sum of squares
d. The degrees of freedom - correct answer ✔✔b. The regression sum of squares
A model has unexplained variation of 153.47 and total variation of 1234.50. What is the 𝑅2
value of this model ?a. 0.1243
b. 0.8756
c. 0.95
d. 1.04 - correct answer ✔✔b. 0.8756
A researcher is interested in the determinants of monthly consumption of natural gas in North
Carolina. She estimates a simple model with only mean monthly temperature as the
independent variable. What does the 𝑅2of this model represent?
a. The variance of the coefficient on mean temperature
b. The percent of variation in gas consumption explained by variations in mean temperature
c. The expected increase in gas consumption associated with a one unit increase in mean
temperature
d. The mean d - correct answer ✔✔b. The percent of variation in gas consumption explained by
variations in mean temperature
,Consider the following sample regression equation: Y bar = 27 ― 5 ∗ 𝑥1 + 2 ∗ 𝑥2. When 𝑥1 is
equal to 0 and 𝑥2 is equal to 1, the dependent variable is equal to 19. What is the residual (the
error) fort his observation?
a. -5
b. 27
c. -10
d. 4 - correct answer ✔✔c. -10
Which of the following variables is categorical?
a. Time
b. Cost
c. Sex
d. Weight - correct answer ✔✔c. Sex
researcher models 𝑔𝑎𝑠 = 𝐵0 + 𝛽1 ∗ ℎ𝑖𝑔ℎ + 𝛽2 ∗ 𝑙𝑜𝑤. What is the predicted change in gas ifboth
high and low increase by 1 unit?
a. 𝛽0
b. 𝛽0 + 𝛽1 + 𝛽2
c. 𝛽0 + 𝛽1
d. 𝜷𝟏 + 𝜷𝟐 - correct answer ✔✔d. 𝜷𝟏 + 𝜷𝟐
Consider the sample regression equation 𝑦 = 15 + 2𝑥1 +7𝑥2 - 𝑥3.
What is the predicted value of the dependent variable when 𝑥1 = 2, 𝑥2 = 1, and 𝑥3 = 4?
a. 15
b. 22
c. 26
d. 31 - correct answer ✔✔b. 22
, Consider the sample regression equation 𝑦 = 15 + 2𝑥1 +7𝑥2 - 𝑥3.
What is the predicted change in Y hat when 𝑥1 increases by 1 unit, 𝑥2does not change, and
𝑥3increases by 1 unit?
a. Decrease 2 units
b. Decrease 1 unit
c. Increase 1 unit
d. Increase 2 units - correct answer ✔✔c. Increase 1 unit
Consider the sample regression equation 𝑦 = 15 + 2𝑥1 +7𝑥2 ― 𝑥3. What is the value of the
residual when 𝑥1 is 0, 𝑥2 is 0, 𝑥3 is 5, and Y is 20?
a. 10
b. 15
c. 20
d. 25 - correct answer ✔✔a. 10
What is one advantage of using dummy variables?
a. They can take any possible value, making it easier to work with
b. They are simpler to add to your model than other variables.
c. They allow you to capture qualitative measures.
d. They have no advantage over other variables - correct answer ✔✔c. They allow you to
capture qualitative measures
In a multiple regression analysis involving 12 independent variables and 166 observations,SSR =
878 and SSE = 122. Thus, the coefficient of determination is __________.
a. 0.139
b. 0.122