Chapter 4 QUIZ

TRUE OR FALSE

Question 4.311

1. True or false: Scatterplots are constructed with the variable on the horizontal axis and the variable on the vertical axis.

Question 4.312

2. True or false: The intercept measures the strength of the linear relationship between two numerical variables.

FILL IN THE BLANK

Question 4.313

3. The “hat” over the in indicates that it is a(n) __________ of .

Question 4.314

4. We interpret the slope of the regression line as the estimated change in per __________ increase in .

SHORT ANSWER

Question 4.315

5. Making predictions based on -values that are beyond the range of the -values in our data set is called what?

Question 4.316

6. Values of close to −1 indicate what type of relationship between the two variables?

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CALCULATIONS AND INTERPRETATIONS

High and Low Temperature. Use the following information for Exercises 7–14. The low and high temperatures (in degrees Fahrenheit) for a sample of eight cities are shown in the following table.

Low temperature High temperature
0 24
10 32
10 38
20 36
20 44
30 45
30 53
40 59
40 65

Question 4.317

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7. Construct a scatterplot of high temperature versus low temperature.

Question 4.318

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8. Based on your scatterplot, would you characterize the linear relationship, if any, as positive or negative?

Question 4.319

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9. Compute the regression equation of high temperature versus low temperature.

Question 4.320

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10. Calculate the three sums of squares: SSR, SST, and SSE.

Question 4.321

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11. Calculate , the standard error of the estimate. What does this number mean?

Question 4.322

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12. Calculate . Comment on how useful the low temperatures are in predicting the high temperatures.

Question 4.323

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13. Use to calculate and interpret the correlation coefficient.

Question 4.324

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14. Find the prediction error for when the low temperature is zero.