Statistics

The paired data below consists of test scores and hours of preparation for 5 randomly selected students.

x    Hours of preparation      5     2     9      6   10

y    Test score                        64   48   72    73   80

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

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

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

4.  Find the standard error . Use the formula or Microsoft Excel Regression

5.  Find the 99% prediction interval for the test score of a person who spent 7 hours preparing for the test given that E = 34.677. Interpret the result.

6.  Find the explained variation.

7.  Find the unexplained variation.

8.  Find the total variation.

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

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