Calculate the absolute and relative values of dispersion

In a town, 25% of the persons earned more than Rs 45000, whereas 75% earned more than Rs 18000. Calculate the absolute and relative values of dispersion.

Given, ${ Q }{ 1 }$ = Rs 18000 ,
${ Q }
{ 3 }$ = Rs 45000
Absolute Value of Dispersion (QD) = ${ Q }{ 3 }$ -
${ Q }
{ 1 }$ / 2 = 45000 - 18000 /2 = Rs 13500
Relative Value of Dispersion (Coefficient of QD) = ${ Q }{ 3 }$ -
${ Q }
{ 1 }$ /
${ Q }{ 3 }$ +
${ Q }
{ 1 }$
= 45000-18000 / 45000+ 18000 = 27000/ 63000 = 0.429