Someone help me solve this shit. I am just not good at this. Any help would be appreciated.

In Professor Friedman's economics course the correlation between the students' total scores before the final examination and their final examination scores is r = 0.6. The pre-exam totals for all students in the course have mean 280 and standard deviation 30. The final exam scores have mean 75 and standard deviation 8. Professor Friedman has lost Julie's final exam but knows that her total before the exam was 300. He decides to predict Julie's final exam score from her pre-exam total.

Question 1. Calculate the slope and intercept of the least squares regression line where the x-variable is pre-exam total score and the y-variable is final exam score.
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Question 2. What is the value of Julie's final exam score predicted by the least squares regression line?


Question 3. Julie complains to Professor Friedman that her final exam score could have been much higher than what is predicted by the least squares regression line. Calculate the proportion of the variation in final exam scores that is explained by the linear relationship between pre-exam scores and final exam scores. (Express your answer as a decimal, not as a percent).

2/9/2009 11:29:26 PM

You want us to do your homework for you?

2/9/2009 11:30:37 PM

This has never been tried.

2/9/2009 11:31:26 PM

2/9/2009 11:31:36 PM

no, if that were the case, i would have put all the questions up there

i am just stuck on this and need some help

any help would be appreciated

[Edited on February 9, 2009 at 11:32 PM. Reason : .]

2/9/2009 11:31:50 PM

2/9/2009 11:37:43 PM

I was a Stats major once.

I'm not anymore for good reason.

2/9/2009 11:40:47 PM

stats is easy as fuck, shit doesnt get hard until you get to 400 level courses and upwards


and bro, this question is ridunculously easy. are you a biology or business major ?

2/9/2009 11:44:36 PM

any help with the problem?

2/9/2009 11:44:39 PM

bro, im not gonna help you cheat....

look at the r though... and the mean and standard deviation...

2/9/2009 11:47:14 PM

you dont have to give me the answer, just help me understand the problem

2/9/2009 11:47:46 PM

y= Mx+b


y is the final exam grade and x is the initial exam grade..... M is the slope and b is y-intercept....


Look in your book on how to figure out M and Y from the standard deviation, mean, and r....... and then you have your solution.....


plug initial test grade into x.... and then you have y

2/9/2009 11:50:50 PM

thx

2/9/2009 11:52:17 PM