Advanced Quants Q47 5LB solution?

user2316 · September 10, 2023, 10:19am

Can anyone please help me with the solution of this question? as I am getting different answers from what I am seeing in the 5LB. Book solution.

Leaderboard · September 10, 2023, 12:34pm

What do you think the answer is, and what’s the book saying?

user2316 · September 12, 2023, 10:13am

My answer is square root of {[(-5)^2+0^2+26^2+(-25)^2] / 4}
=18.2

Leaderboard · September 12, 2023, 10:21am

Assuming that you’re using the first edition of the 5lb book, it’s an error from their side, and they’ve confirmed it. See Errata - 5 lb. Book, 1st Edition - GRE

In other words, 18.2 is the correct answer.

user2316 · September 12, 2023, 2:27pm

Thanks bro!!!

user2316 · September 12, 2023, 4:54pm

Refer to this. It has two distinct formulae.

Leaderboard · September 12, 2023, 5:06pm

OK, and …?

user2316 · September 12, 2023, 5:11pm

Basically, if we want to calculate standard deviation the formula is 1st one, exception is for when it’s sample standard deviation then it would be 2nd formula.