Find standard deviation.?

Question

The differences between two sets of dependent data are 0.11, 0.21, 0.15, 0.12, 0.14. Round to the nearest hundredth.

Answer 1

stdev := sqrt( sum( ( Xi - Xavg )^2 ) / ( n - 1 ) )

Xi = {0.11,0.21,0.15,0.12,0.14}
Xavg = sum(Xi)/5 = 0.146
( Xi - Xavg )^2 = { 1.296, 4.096, 0.016, 0.676, 0.036 } x 10^-3
sum( above ) / ( n - 1 ) = 6.120 x 10^-3 / ( 5 - 1 ) = 1.530 x 10^-3
stdev = sqrt( above ) = 0.039115214

Cheers.