1 Computing the standard deviation Computing the standard de

1. Computing the standard deviation

Computing the standard deviation signa_y of N measurements y_1, y_1,... y_n of a singles quantity y Prove that this sum can be rewritten as This problem is a good exercise using summation notation. Many calculators use the expression on the right to compute the standard deviation. Can you determine why? Is it more efficient? requires that you compute the sum

Solution

yes... because 2nd term is nothing but the first term divided by N.

for left hand expression, we need to calculate ybar then (yi-ybar) then square the same... where for right it is directly squaring yi