# Chapter 1. Regression lines

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Stat Tutor
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2:18

### Question 1.1

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Incorrect. After collecting data, the first thing you should always do is plot your data. In regression we can decide whether the relationship is linear and whether there are outliers from the scatterplot.
Correct. After collecting data, the first thing you should always do is plot your data. In regression we can decide whether the relationship is linear and whether there are outliers from the scatterplot.
Incorrect. Try again.
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### Question 1.2

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Incorrect. From the equation ŷ = 23.00 + 1.15x, y-intercept is 23.00.
Correct. From the equation ŷ = 23.00 + 1.15x, y-intercept is 23.00.
Incorrect. Try again.
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### Question 1.3

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Incorrect. From the equation ŷ = 23.00 + 1.15x, slope is 1.15.
Correct. From the equation ŷ = 23.00 + 1.15x, slope is 1.15.
Incorrect. Try again.
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3:31

### Question 1.4

Incorrect. This is a correct statement.
Correct. This is a correct statement.
Incorrect. Try again.
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### Question 1.5

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Incorrect. Since X is height at age 4 and height is measured in inches, a one-unit increase in X is a one inch increase.
Correct. Since X is height at age 4 and height is measured in inches, a one-unit increase in X is a one inch increase.
Incorrect. Try again.
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### Question 1.6

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Incorrect. y-intercept is the value of Y when X = 0. We could also plug the value of zero into the equation ŷ = 23.00 + 1.15x and get y = 23.00.
Correct. y-intercept is the value of Y when X = 0. We could also plug the value of zero into the equation ŷ = 23.00 + 1.15x and get y = 23.00.
Incorrect. Try again.
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### Question 1.7

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Incorrect. Slope tells us the change in Y for a one-unit increase in X and slope is 1.15.
Correct. Slope tells us the change in Y for a one-unit increase in X and slope is 1.15.
Incorrect. Try again.
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3:56

### Question 1.8

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Incorrect. We often use a regression line for prediction.
Correct. We often use a regression line for prediction.
Incorrect. Try again.
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### Question 1.9

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Incorrect. This is a correct statement.
Correct. This is a correct statement.
Incorrect. Try again.
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