In: Statistics and Probability
No Exercise |
Exercise |
Total |
|
Campus Dormitory |
32 |
58 |
90 |
On-Campus Apartment |
74 |
106 |
180 |
Off –Campus Apartment |
110 |
40 |
150 |
At Home |
39 |
11 |
50 |
Total |
255 |
215 |
470 |
You have now decided to collapse your data into on-campus and off-campus living (use data from #7) 2x2 table. Determine if there is a difference between living on-campus or off-campus and exercise status (yes exercise, no exercise).
1. state the null and alternative hypothesis
2. determine a
3. select chi square tool
4. Fine the critical value
5. reject or fail to reject
6. State the conclusion
Assume the level of significance to be 5%.
Chi-Square Independence test - Results |
(1) Null and Alternative
Hypotheses The following null and alternative hypotheses need to be tested: H0: The two variables - living on-campus or off-campus and exercise status are independent Ha: The two variables - living on-campus or off-campus and exercise status are dependent This corresponds to a Chi-Square test of independence. (2) Degrees of Freedom The number of degrees of freedom is df = (4 - 1) * (2 - 1) = 3 (3) Critical value and Rejection Region Based on the information provided, the significance level is α=0.05, the number of degrees of freedom is df = (4 - 1) * (2 - 1) = 3, so the critical value is 7.8147. Then the rejection region for this test becomes R={χ2:χ2>7.8147}. (4)Test Statistics The Chi-Squared statistic is computed as follows: (5)P-value The corresponding p-value for the test is p=Pr(χ2>58.5666)=0 (6)The decision about the null hypothesis Since it is observed that χ2=58.5666>χ2_crit=7.8147, it is then concluded that the null hypothesis is rejected. (7)Conclusion It is concluded that the null hypothesis Ho is rejected. Therefore, there is enough evidence to claim that the two variables - living on-campus or off-campus and exercise status are dependent, at the 0.05 significance level. Conditions: a. The sampling method is simple random sampling. b. The data in the cells should be counts/frequencies c. The levels (or categories) of the variables are mutually exclusive. |