Introduction to Probability and Statistics | Liberty University
100-Question Original Practice Examination | 2026/2027 Edition
1. A linear model predicts weekly output for retail branches as y-hat = 30 + 4x. What is the predicted
output when x = 3?
A) 42
B) 34
C) 46
D) 12
Correct Answer: A) 42
Rationale: Substitute x = 3 into the fitted equation: 30 + 4(3) = 42. The intercept alone is the forecast at x = 0, while the
slope alone is the change per additional unit. Predictions use both terms at the specified x.
2. A linear model predicts weekly output for service centers as y-hat = 35 + 5x. What is the predicted
output when x = 4?
A) 20
B) 55
C) 60
D) 40
Correct Answer: B) 55
Rationale: Substitute x = 4 into the fitted equation: 35 + 5(4) = 55. The intercept alone is the forecast at x = 0, while the
slope alone is the change per additional unit. Predictions use both terms at the specified x.
3. A linear model predicts weekly output for online campaigns as y-hat = 40 + 6x. What is the predicted
output when x = 5?
A) 46
B) 70
C) 76
D) 30
Correct Answer: B) 70
Rationale: Substitute x = 5 into the fitted equation: 40 + 6(5) = 70. The intercept alone is the forecast at x = 0, while the
slope alone is the change per additional unit. Predictions use both terms at the specified x.
4. A linear model predicts weekly output for warehouse teams as y-hat = 45 + 7x. What is the predicted
output when x = 6?
A) 42
B) 52
C) 87
D) 94
BUSI 230 | Exam 4 | Independent Practice 1
, Correct Answer: C) 87
Rationale: Substitute x = 6 into the fitted equation: 45 + 7(6) = 87. The intercept alone is the forecast at x = 0, while the
slope alone is the change per additional unit. Predictions use both terms at the specified x.
5. A linear model predicts weekly output for restaurant locations as y-hat = 50 + 8x. What is the
predicted output when x = 7?
A) 114
B) 106
C) 58
D) 56
Correct Answer: B) 106
Rationale: Substitute x = 7 into the fitted equation: 50 + 8(7) = 106. The intercept alone is the forecast at x = 0, while the
slope alone is the change per additional unit. Predictions use both terms at the specified x.
6. For retail branches, the estimated regression slope is 4. Interpret this coefficient if x measures
advertising units and y measures sales units.
A) Predicted sales increase by 4 units per additional advertising unit
B) Predicted sales equal 4 when advertising is zero
C) Advertising increases by 4 units for each sale
D) Sales always increase exactly 4 units in every observation
Correct Answer: A) Predicted sales increase by 4 units per additional advertising unit
Rationale: In a linear model the slope is the change in predicted response for a one-unit increase in the predictor. It
describes an average fitted relationship, not a guarantee about every observed sale. The intercept, not the slope, supplies
the fitted response at zero advertising.
7. For service centers, the estimated regression slope is 5. Interpret this coefficient if x measures
advertising units and y measures sales units.
A) Predicted sales increase by 5 units per additional advertising unit
B) Advertising increases by 5 units for each sale
C) Predicted sales equal 5 when advertising is zero
D) Sales always increase exactly 5 units in every observation
Correct Answer: A) Predicted sales increase by 5 units per additional advertising unit
Rationale: In a linear model the slope is the change in predicted response for a one-unit increase in the predictor. It
describes an average fitted relationship, not a guarantee about every observed sale. The intercept, not the slope, supplies
the fitted response at zero advertising.
8. For online campaigns, the estimated regression slope is 6. Interpret this coefficient if x measures
advertising units and y measures sales units.
A) Predicted sales equal 6 when advertising is zero
B) Sales always increase exactly 6 units in every observation
C) Predicted sales increase by 6 units per additional advertising unit
BUSI 230 | Exam 4 | Independent Practice 2