Write a polynomial function of nth degree that has the given real roots. n=3; zeros: -1 and x=3 is a double root​

Plot the points (0,6), (3,15.8), and (9.5,0) using the graphing tool, and find the function

Ftara spends $219 a month for her car payment and she makes $3,200 a month, what percent of her monthly income is spent on her car payment?

Extra points! find the missing dimension! need asap