Res/342 Wk5

Week 5 E-Text Exercise Chapter 12, 13, 14
RES/342
February 08, 2011

Week 5 E-Text Exercise Chapter 12, 13, 14
Week 5 Chapter 12, 13, 14

1. (a) How does correlation analysis disaccord from regression analysis? (b) What does a correlation coefficient reveal? (c) assure the nimble rule for a significant correlation and inform its limitations.
(d) What sums be needed to calculate a correlation coefficient? (e) What atomic number 18 the dickens ways of block outing a correlation coefficient for conditional relation?

A) Correlation analysis attempts to identify the kindred (if any) between two variables of interest, while regression analysis uses one (or more) independent variable (the xs) to predict the value of another dependent (y) variable by means of a predictive model.

B) The correlation coefficient can allot values between -1 and 1. The sign signifies whether the relationship is positive or negative and the distance from 0 signifies the strength of the relationship. In particular, the relationship described in this way is a linear relationship.

C) This quick rule is specific to your class. If youll tell me the rule, Ill be happy to cede you its limitations.

D) You need the sum of the (xy). You need the sum of (x), the sum of (y). These are for calculating x-bar, y-bar.



You also need the sum of square xs and ys.

E) in that respect is a t-test. The test statistic is r/(sqrt((1-r^2)/(N-2))
There is also a z-test. The formula is Z = ln[|(r+1)/r-1)|]/2
There are more than fair(a) these two. For example, the quick rule that you mentioned above. There is also an F-test, I believe. You should meditate your notes to see which ones are being referred to here.

12.48 In the following regression, X = weekly pay, Y = income tax withheld, and n = 35 McDonalds employees. (a) Write the fitted regression equation. (b) State the degrees of freedom for a twotailed test for zero slope, and use Appendix D to find the full of life value at ? = .05. (c) What is your conclusion about the slope?...If you indigence to get a full essay, order it on our website: Ordercustompaper.com



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