Question 1074911
HI=-42.379 + 2.049T + 10.143*100 - 0.225T*100 - (6.838 x 10^-3)T^2 - 0.0548*10000 + (1.229 x 10^-3)T^2*100 + (8.528 x 10^-4)T*10000- (1.990 x 10^-6)T^2*10000

HI=-42.379 + 2.049T + 1014.3 - ,22.5T - (6.838 x 10^-3)T^2 -548+ (1.229 x 10^-1)T^2 + 8.528T- (1.990 x 10^-2)T^2.
85=-42.379+174.165+10.143R-19.125R-49.406-0.055R^2+8.880R+0.072R^2-0.014R^2
85=82.38+0.003R^2-0.182R
0.003R^2-0.182R-2.62=0
quadratic formula
denominator is 0.006
0.182+/- sqrt (0.033124+4(0.003)(2.62); sqrt term is 0.03144, and root is 0.1773
0.182+/-0.1773 is 0.359 no negative root used
divide by 0.006 to get 59.83% or 60%.