If sum of aquares of items =2,430, arithmctic mean =7, and number of items=12, find the coefficient of variation.

Explanation

Given: `sumX^(2)=2,430, barX=7`, N=12
`sigma=sqrt((sumX)/(N)-(barx)^(2))`
`=sqrt((2,430)/(12)-(7)^(2))=sqrt(202.5-49)`

`=sqrt(153.5)=12.39`
`CV=(sigma)/(barX)xx100`
`=(12.39)/(7)xx100=177`
Coefficient of Variation =1.77.