Chapter 11.2, Problem 1AC

Satellite Dishes in Restricted Areas

The Senate is expected to vote on a bill to allow the installation of satellite dishes of any size in deed-restricted areas. The House had passed a similar bill. An opinion poll was taken to see whether how a person felt about satellite dish restrictions was related to his or her age. A chi-square test was run, creating the following computer-generated information.

Degrees of freedom d.f. = 6

Test statistic χ² = 61.25

Critical value C.V. = 12.6

P-value = 0.00

Significance level = 0.05

1. Which number from the output is compared to the significance level to check if the null hypothesis should be rejected?

2. Which number from the output gives the probability of a type I error that is calculated from your sample data?

3. Was a right-, left-, or two-tailed test run? Why?

4. Can you tell how many rows and columns there were by looking at the degrees of freedom?

5. Does increasing the sample size change the degrees of freedom?

6. What are your conclusions? Look at the observed and expected frequencies in the table to draw some of your own specific conclusions about response and age.

7. What would your conclusions be if the level of significance were initially set at 0.10?

8. Does chi-square tell you which cell’s observed and expected frequencies are significantly different?