Answer
$95$
Work Step by Step
$A= 452$
$C=285$
$T=20$
$Y=3475$
$I=7$
$\text{Rating} = \dfrac{\left(250 \,\dfrac{C}{A} \right)+ \left(1000 \, \dfrac{T}{A} \right)+ \left(12.5 \, \dfrac{Y}{A} \right)+6.25 -\left(1250 \, \dfrac{I}{A}\right)}{3}$
$\text{ Rating } = \dfrac{\dfrac{250C+1000T+12.5Y-1250I}{A}+6.25}{3}$
$\text{Rating } = \dfrac{\dfrac{250\times 285 +1000 \times 20 + 12.5 \times 3475 -1250 \times 7}{452}+6.25}{3}$
$\text{Rating } \approx \dfrac{278.623+6.25}{3}$
$\text{ Rating } \approx 95$