In exercise 5.10, we proved that f(y1,y2) = is a valid joint probability density function for y1, the amount of pollutant per sample collected above the stack without the cleaning device, and y2. the amount collected above the stack with the cleaner. are the amounts of pollutants collected with and without the cleaning device independent?

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204

it's undefined because anything multiplied by 0 is 0. that said, 7 days is 168 hours