Unformatted text preview: Practice Test 2C 1. As specifically as possible, explain when you use N
1 in the denominator when calculating the standard deviation. 2. Why are things like the covariance or third moment standardized? How does this help? 3. Draw a scatter diagram that shows a strong association between X and Y, but for which the correlation coefficient would equal zero. 4. WT= A1 + 4HT + 13MALE. Amy (a woman) is 70 inches tall and Bob (a man) is 67 inches tall. What is our best prediction for the differences in their weight? In other words, who probably weighs more and by how much? Show work. 5. In the equation WT=a1 + b2HT+ b4MALE, as precisely as possible (without using the words “holding…constant”) explain what b4 is measuring. 6. Why can’t we use Pearson’s R to interpret an asymptotic or parabolic scatter plot? 7. Calculate Chi
Squared and Cramer’s V. Accounting Finance Marketing B.A B. Eng. B.B.A Other 8. Let’s say that the correlation between hours studied and test score is 0.5 for men. Lets say that the correlation between hours studied and test score is 0.4 for women. Let’s say that men study quite a bit more than women, but that women score quite a bit higher than men. Is the correlation between hours studied and test score most likely to be A) less than 0.4, B) between 0.4 and 0.5, C) greater than .5. There is no need to explain. I strongly suggest drawing the scatter diagram of them combined. Is should help you figure out the answer. 9. Calculate the concordant and discordant. Hi 4 10 Y Lo 3 7 31 8 12 10 13 16 10 5 16 7 17 7 Hi Lo X 10. Standardize the sample for the above data. 11. Calculate GAMMA from the data in number 9. 12. Calculate Somer’s D for the data given in number 9. 13. When we talk about the Ordinary Least Squares, what are we guessing? 14. Draw a scatter plot that shows a positive relationship but has a correlation of coefficient of 0. 15. What does r tell us? 16. What is the significance of the intercept in the Regression Line equation? 17. On a graph with 4 quadrants plot a point that describe the following: a. A weak negative relationship b. A strong positive relationship c. No relationship d. A weak positive relationship e. A strong negative relationship 18. From the above problem, what do parts A and D in regards to part C? ...
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- Fall '10
- Cramer, the 00, Somer, a 00