Joan believes the best way to play roulette is to place a bet on a 6 block of numbers as her probability of winning is 638. She decides to place a $20 bet with this probability. She will win $100 (and keep her bet!) if one her numbers come up but she will lose if any other number is shown, a probability of 3238. What is the expected value for Joan? Round to the nearest cent. Do not round until your final calculation.

26?

step-by-step explanation:

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

the answer is 13

step-by-step explanation:

5*5=25

12*12=144

25+144=169

169^2=13