# Problem 1

If n =10, = 12 and = 1530 find coefficient of variation

# Solution

${\displaystyle {\frac {\sum x}{n}}={\bar {x}}}$

${\displaystyle \sum {x}={{\bar {x}}\times {n}}}$

${\displaystyle \sum {x}={12\times {10}}}$

${\displaystyle \sum {x}=120}$
σ=${\displaystyle {\sqrt {{\frac {\sum {x^{2}}}{n}}-({{\frac {\sum x}{n}})^{2}}}}}$
σ=${\displaystyle {\sqrt {{\frac {1530}{10}}-{144}}}}$
σ=${\displaystyle {\sqrt {153-144}}}$
σ=${\displaystyle {\sqrt {9}}}$
σ=3