Help!! I am struggling to figure out the effect size formula ( the spooled part) to get the effect size calculation. I have two groups (55 and 33) both with a SD of 12. I am particularly not understanding the s 2 over 1 part.
i have the main formula: u1-u2/Spooled, but the spooled formula is quite confusing.
(I am a PhD Psych major and this is an adv. stats. class)
I appreciate any help, I am completely stuck until I can get this effect size calculated!
Thanks for your reply, but isn't the "s" what I have to calculate to finish the 1st formula?
ok, so the sample variances are 144?
I get .0308 if I am on the right track?
The professor wanted us to use a s=12 for both, but it looks like I am still way off?
Here is my work: 54(144) + 32(144); 7776+4752=12528
divided by 54+32=86
yes, i saw I missed the SQ step. But we take N-1(55-1 and 33-1) for both groups which puts us at 86 instead of 88, right?
I see. It looks like the formula in my textbook and yours are different there. But I know how to get there now. I can't thank you enough for your time and patience-you have been a Godsend!
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