variance formula

[golf10s]

I've noticed the Barron's DAT guide says for the variance formula, the squared deviation (numerator) is divided by n-1 and so does a statistics notes online on google. But I've noticed all the answers in every single one of DAT study guide book answer was calculated by dividing by n, NOT n-1. Does anyone know which is the correct?

I'm freaking out cuz my DAT is on the 28th and I seem to keep finding all these ambiguous sources!!!!

Thanks.

😱

 

[Balki]

I found an explanation to your question
here:
http://mathforum.org/library/drmath/view/52722.html
I wouldn't trust barron's still , Because personally I found way to many mistakes in their text. Good luck and hope this helps
I have my DAT on 25th , it's in about eh say 40 hours away, I'll let you know if I have any weird variance questions.

 

[rsweeney]

It's always nice to get info from a perfect stranger