okay so i am trying to model a cubic equation to fit my curve

my base curve is specifications:

x value-0 to 6.19
amplitude-0.77
amplitude coordinates-3.73,0.77
x intercepts-0,0 and 6.19 , 0

this is my curve and i have to make a equation and include transformations to make this equation ax3+bx2+cx fit that curve

x (x-6.19) (x+a) = 0

when x = 3.73, y = .77

3.73 (3.73-6.19)(x+a) = .77

3.73 (-2.46)(x+a) = .77
x+a = - .0949
a = .0949 call it .095
so
(x^2-6.19x)(x+.095) = 0
x^3 -6.19x^2 +.095x - .587 = y