# Correlation Coefficient - Have I done this right?

• Jan 12th 2008, 11:46 AM
leaaa
Correlation Coefficient - Have I done this right?
Hey,

I have an exam on tuesday, and just revising.

I would like to know if I have done this right.

The reason I have wrote down the whole number from the calculator throughout the working out is a longggg story... basically because I am using a different formula to the one we have revised at university, where I have to find the value of X in this one....yes I do know how to round up but this wont give a definate answer as to whether the correlation is negative or positive.. but anyway here it is, I done it on Word and then print screened it...

http://i18.photobucket.com/albums/b1...nx/Q1PART1.png
http://i18.photobucket.com/albums/b1...nx/Q1Part2.png
http://i18.photobucket.com/albums/b1...nnx/Q1PRT3.png
• Jan 13th 2008, 01:47 AM
earboth
Quote:

Originally Posted by leaaa
Hey,

I have an exam on tuesday, and just revising.

I would like to know if I have done this right.

...

Hello,

1. why don't you use the build-in function of Excel to calculate the correlation coefficient?
It will return r = 0,877458866

2. I've got a different value for $\sum \gamma^2 = 15.05$

3. All other calculations seem to be OK.
• Jan 13th 2008, 03:57 AM
leaaa
Quote:

Originally Posted by earboth
Hello,

1. why don't you use the build-in function of Excel to calculate the correlation coefficient?
It will return r = 0,877458866

2. I've got a different value for $\sum \gamma^2 = 15.05$

3. All other calculations seem to be OK.

Hey, thanks for your reply, I cant use excel in my exam its a written one. I dont really understand where they got those values from, how did you get 15.05?

Thanks x
• Jan 13th 2008, 07:33 AM
earboth
Quote:

Originally Posted by leaaa
Hey, thanks for your reply, I cant use excel in my exam its a written one. I dont really understand where they got those values from, how did you get 15.05?

Thanks x

Hello,

1. I've made a silly typo. But the final result I got differs slightly from your's.

2. To show you where these values come from I attach the complete spread-sheet.

I hope this will help a little bit further on.
• Jan 13th 2008, 08:38 AM
leaaa
hey :) thanks for your reply and your help, i understand where this value comes from now.

So would you say that i got this question wrong? As the difference between my reult and yours is 0.1 or something? x