Statitistics

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. 

2. Based on the linear correlation coefficient r, 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 formula or MS Excel.

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

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 effect the results of the regression analysis?  Is this data point an outlier, influential point or both?  Explain.