express profit as function of number of items sold algebra

Question

The table below shows the profit, p(x), in dollars from selling x items

X 1 2 3 6 9 14

Y 90.6 106.4 112.4 71.6 -57.4 -468.4

Using your calculator to do a quadratic regression, express the profit as a function of the number of items sold. 

round to 1 decimal place

P(X)=

Answer 1

The quadratic function in X takes the form as

P(X) = Ax^2 + Bx + C

Now we have X and P(X) values, so we can submit that in the calculator and get the coefficients A, B, and C.

The final answer would be

P(X) = -5.3 X^2 +38.1X + 58.0