Students’ grade in statistics and their degree of happiness with school ...

Using the following information, complete the table and compute the r and r2 for the data:
Students’ grade in statistics and their degree of happiness with school
Student Grade (X) Happy (Y) X2 Y2 XY
Judy 8 9
Tom 9 10
Mike 4 2
Barb 10 9
Mary 3 1
Totals:
N=5

 

2. Is there a significant relationship between the grades earned in statistics and degree of happiness with school? Explain

 

3. r2= ?

 

4. What percentage of the variation in a student’s level of happiness can be explained by its relationship to grade earned in statistics?

True or False:
1. Parametric tests are more powerful, but have stricter requirements.
2. The size of “r” indicates how strong the relationship is between the variables.
3. As the sample size increases, the value of “r” necessary to get significance increases.
4. If N=20, one-tailed test, r=.45, significant level=.25. We would reject the null hypothesis if we have a predetermined significant level p=.05.
5. If N=52, two-tailed test, r=.28, p=.05. We would reject the null hypothesis if we have a predetermined level of p=.05.
6. An “r2”=36, this tells us that we have a 36% chance of predicting correctly.
7. Correlations are non-linear relationships.
8. Correlation coefficients range from 0 to +1.
9. Pearson’s “r” fails to provide information about the direction of the relationship.
10. For a perfectly positive relationship, “r”=+1.
11. If there is no relationship between the variables, r=0.
12. An “r” of -.90 would indicate a strong relationship between the two variables.