Answer:
2.65
Step-by-step explanation:
Multiply each payout by its probability, then add those products.
See the attached image.
The first column has the payouts. The second column has the probabilities. The third column has the results of multiplying a payout by its probability.
The sum of the entries in the third column is 2.65
To find the y-intercept, simply set the value of x equal to 0, and solve for y, or f(x).
f(x) = 0^2 - 3(0) - 40
f(x) = -40
<h3>The y-intercept is -40.</h3>Because this is a 2nd degree polynomial, we cannot find the x-intercepts in one step, and must instead use one of a few different methods.
In this case, we're going to use the quadratic formula:
Plug in the values.
3 +/- √(-3^2 + 160) / 2
3 +/- √169 / 2
3 +/- 13 / 2
(3 + 13) / 2 = 16 / 2 = 8
(3 - 13) = -10 / 2 = -5
<h3>The x intercepts are 8, and -5.</h3>