What are the mean and standard deviation of {34, 98, 20, -1200, -90}?

2 Answers
Apr 11, 2018

Mean = 227.6
Standard deviation = 489.9492

Explanation:

Calculate the mean as the sum of the numbers divided by the number of observations

Mean =34+98+201200905=227.6

Calculate the standard deviation as the square root of the sum of the squared difference each observation and the mean divided by the number of observations.

Standard deviation =(34227.6)2+(98227.6)2+(20227.6)2+(1200227.6)2+(90227.6)25=489.9492

Apr 11, 2018

Mean: 227.6, standard deviation is 489.9492

Explanation:

Data: S={34,98,20,1200,90}

Mean : s5=227.6

Variance square differences are (34(227.6))2=68434.56,

(98(227.6))2=106015.36, (20(227.6))2=61305.76,

(1200(227.6))2=945561.76, (90(227.6))2=18933.76

Average variance square differences is

σ2=1200251.25=240050.24

Standard deviation is σ2=489.9492