Question

For a certain firm the score of test taken for sales men and sale by them is as follows: Find covariance between score and sale.

scores	$14$	$19$	$24$	$21$	$26$	$22$	$15$	$20$	$19$
Sales(in $000$ Rs.)	$31$	$36$	$48$	$37$	$50$	$45$	$33$	$41$	$39$

• A. $20.00$
• B. $6.36$
• C. $14.32$
• D. $15.37$

Answer 1

The correct option is D $15.37$

$n=9.$

$u=\frac{\sum x}{n}=\frac{180}{20}=20,$

$v=\frac{\sum y}{n}=\frac{360}{9}=40.$

$convariance=\frac{\sum \left[\right(x-u\left)\right(y-v\left)\right]}{n-1}=\frac{123}{8}=15.37$