What is the variance of {15, 4, 2, -7, 8, 10}?

1 Answer
David Britz
Mar 19, 2016

47.9

Explanation:

I'm going to assume you mean population variance (sample variance will differ slightly).

#sigma^2=(Sigmax^2-(Sigmax)^2/N)/N#

Please differentiate between the two. The first sign says "add the squares of your numbers", the second says "add first, THEN square the sum"

#Sigmax^2=15^2+4^2+...+10^2=458#
#(Sigmax)^2=(15+4+2+...)^2= 1024#
#N=6#

#sigma^2=(458-(1024/6))/6=47.9#

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