## Elementary statistics

This test is due in class on Monday, December 6.
Questions 1-5 are worth 2 points each. Circle the best answer. Justification is not required.

1. The stronger the linear relationship between paired-sample data X and Y, the closer the correlation coefficient is to +1 or -1. True 2. Suppose you calculate the correlation coefficient r between temperature X and volume Y. Then you recalculate, using Celsius instead of Fahrenheit for X. Will the value of the correlation
coefficient r change?
Yes
3. Suppose statisticians determined that there is a significant positive correlation between gun ownership and violent crime. Does this prove that guns cause violent crime?
Yes
4. Suppose that you found that the correlation coefficient between X and Y is r = -0.568 and you
determined that the critical value for the correlation coefficient at the 5% significance level in Table A-6 is .444. Are X and Y significantly correlated? Yes 5. The variables X and Y in the following scatter plot have a positive correlation coefficient. The remaining questions are worth 4 points each. Show your work for complete and partial
credit. Work carefully, especially with data entry into lists and/or matrices.

Questions 6 and 7: The paired data below consist of the test scores of four randomly selected Math 142 students and the numbers of hours they studied for this test. 6. What is the value of the correlation coefficient r. How did you get your answer?