Chapter 1. Introduction to Regression

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Stat Tutor
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Questions 1-3

1:36

Question 1.1

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Incorrect. The letter “X” is always used to represent the explanatory (or predictor) variable.
Correct. The letter “X” is always used to represent the explanatory (or predictor) variable.
Incorrect. Try again.
2

Question 1.2

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Incorrect. The letter “Y” is always used to represent the response (or the predicted) variable.
Correct. The letter “Y” is always used to represent the response (or the predicted) variable.
Incorrect. Try again.
2

Question 1.3

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Incorrect. We use “X” to predict “Y”.
Correct. We use “X” to predict “Y”.
Incorrect. Try again.
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Questions 4-5

2:52

Question 1.4

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Incorrect. In this course we use the lower case letter “b” to represent slope.
Correct. In this course we use the lower case letter “b” to represent slope.
Incorrect. Try again.
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Question 1.5

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Incorrect. The symbol ŷ is pronounced “y-hat” and represents the predicted y value.
Correct. The symbol ŷ is pronounced “y-hat” and represents the predicted y value.
Incorrect. Try again.
2

Questions 6-11

5:55

Question 1.6

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Incorrect. y-intercept is the point at which the line intercepts the y-axis. So, it is the value of Y when X = 0.
Correct. y-intercept is the point at which the line intercepts the y-axis. So, it is the value of Y when X = 0.
Incorrect. Try again.
2

Question 1.7

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Incorrect. Slope is often described as “rise over run.” The rise is in Y and the run is in X. So, slope tells us the change in Y for every one unit increase in X.
Correct. Slope is often described as “rise over run.” The rise is in Y and the run is in X. So, slope tells us the change in Y for every one unit increase in X.
Incorrect. Try again.
2

Question 1.8

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Incorrect. When slope is positive, Y increases as X increases.
Correct. When slope is positive, Y increases as X increases.
Incorrect. Try again.
2

Question 1.9

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Incorrect. When slope is positive, Y increases as X increases.
Correct. When slope is positive, Y increases as X increases.
Incorrect. Try again.
2

Question 1.10

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Incorrect. We use X to predict Y and Y is the response variable. Since we want to predict GPA, the response variable is GPA.
Correct. We use X to predict Y and Y is the response variable. Since we want to predict GPA, the response variable is GPA.
Incorrect. Try again.
2

Question 1.11

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Incorrect. We use X to predict Y and X is the explanatory or predictor variable. Since we want to use car weight to predict car mileage, the explanatory variable is car weight.
Correct. We use X to predict Y and X is the explanatory or predictor variable. Since we want to use car weight to predict car mileage, the explanatory variable is car weight.
Incorrect. Try again.
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