I am trying to find what value X needs to be to make the maximum value for Y, but I am not sure how to do that!

Code:`X | Y`

---------

0.6 | 1112

0.7 | 1113.5

0.8 | 1107

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- May 21st 2011, 10:55 AMjennifer92Maximization Problem
I am trying to find what value X needs to be to make the maximum value for Y, but I am not sure how to do that!

Code:`X | Y`

---------

0.6 | 1112

0.7 | 1113.5

0.8 | 1107

- May 21st 2011, 11:14 AMTKHunny
x = 0.7?

If this is not the correct answer, you'll have to provide a better problem statement. - May 21st 2011, 11:27 AMjennifer92Code:
`( 80(1-x) + 107 )( 5x + 5 ) = y`

If X = 0.66 then Y = 1113.86

If X = 0.67 then Y = 1113.89

If X = 0.68 then Y = 1113.84

So I know the answer is somewhere between 0.66 and 0.67 - May 21st 2011, 01:57 PMtopsquark
- May 21st 2011, 03:54 PMjennifer92
I can solve the problem using any method!

- May 21st 2011, 04:40 PMtopsquark
Okay, so let me ask you the following... Your problem boils down to finding the maximum of $\displaystyle y = -400x^2 + 535x + 935$. This is a parabola that opens downward, so it has a maximum. The maximum will lie on the axis of symmetry of the parabola and is, in fact, at the vertex. Can you find the vertex of this parabola?

-Dan - May 21st 2011, 04:48 PMjennifer92
- May 21st 2011, 05:13 PMtopsquark
- May 21st 2011, 05:36 PMjennifer92
Thanks for your help, I got it figured out.