Correlation and Regression Analysis

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Module 5 Homework Assignment

The paired data below consists of test scores and hours of preparation for 5 randomly selected students. Use this data set to answer the questions below:

x Hours of preparation 5 2 9 6 10

y Test score 64 48 72 73 80

1. Use the given data to find the correlation coefficient r, regression equation and scatter plot in MS Excel.

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2. Based on the linear correlation coefficient r, is this a good model? Explain.

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3. What is the best predicted test score for a student who spent 7 hours preparing for the test?

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4. Find the standard error . Use formula or MS Excel.

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5. Find the 99% prediction interval for the test score of a person who spent 7 hours preparing for the test.

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6. Find the explained variation.

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7. Find the unexplained variation.

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8. Find the total variation.

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9. Find the value of r2 and explain its meaning.

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10. If the data point ( 3, 100) is added to the data set, how would this effect the results of the regression analysis? Is this data point an outlier, influential point or both? Explain.

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