# Determining the sum of squares, variance, standard deviation

Please help me calculate the ss, variance and standard deviation for this.

n=4 scores are 7, 4, 2, 1

(do i figure the mean here 1st? 3.5?)

ss____

variance____

standard deviation____

Also if a population has a mean of 80 and standard deviation of 20 would the score of x=70 be considered extreme in the sample?

If the standard were 5 would a score of x=70 be considered extreme?

https://brainmass.com/statistics/statistical-theory/determining-sum-squares-variance-standard-deviation-583598

#### Solution Preview

1. mean=(7+4+2+1)/4=3.5

SS=(7-3.5)^2+(4-3.5)^2+(2-3.5)^2+(1-3.5)^2=21

Variance=21/(4-1)=7

Standard ...

#### Solution Summary

The solution gives detailed steps on determining the sum of squares, variance, standard deviation and extreme value in the sample.

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