# Math Help - Quadratic Transformations urgent

I need a little help with this problem...

Number of coputers produced-Profit
50---------------------------$5100 100--------------------------$5600
150--------------------------$1100 A-Find a quadratic function that describes the profit as a function of the number of computers produced. B-Predict the number of computers that need to be produced to maximize the profit. C-Predict the max profit, assuming that all business conditions stay the same. For a i have -1.2x^2+189.7+-1390.... i dont know if its right And for b i found 79 computers.... and for c i found$6107.1

i dont think this makes since... this would mean that between 50-100 it would have hit its max and dropped

2. I get ...

$P = -x^2 + 160x - 400$

max profit at $x = 80$ computers

$P(80) = 6000$

3. Thanks! that makes more sense, i must have had rounded somethin wrong. or wasnt supposed to. But may i ask how did you get the equation?

4. quadratic regression on a TI-84 calculator.

5. oh ok i think i got it now....so i enter data in to list. and quadreg it? and im on ti-83 would that matter?

6. TI-83 does it the same way.

7. k thanks agn i appreciate it