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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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