# can this formula be used?

• Jan 14th 2008, 04:37 AM
leaaa
can this formula be used?
Can this formula:

http://www.cnr.berkeley.edu/ucce50/a...ch/Image27.gif

...be used for correlation coefficient, when in my exam paper I am given the vaules:

Sxy Sxx Syy??
• Jan 14th 2008, 04:59 AM
colby2152
Correlation coefficent is equal to: $\displaystyle \frac{COV[XY]}{\sigma_x\sigma_y}$

• Jan 14th 2008, 05:00 AM
leaaa
Quote:

Originally Posted by colby2152
Correlation coefficent is equal to: $\displaystyle \frac{COV[XY]}{\sigma_x\sigma_y}$

well it does help, its just the forumla that i have posted above is the formula which i am used to using.

So could i use that formula in any question for correlation coefficient?

xx
• Jan 14th 2008, 05:01 AM
colby2152
Quote:

Originally Posted by leaaa
well it does help, its just the forumla that i have posted above is the formula which i am used to using.

So could i use that formula in any question for correlation coefficient?

xx

Yes, you may use that formula. It is the same one as I provided, but in sum notation. You said that you only have the joint standard deviations though.