After Day 7 the Second would have more water.
therefore there exist two real solutions.
In total, there are 3 real roots. But, real roots are also complex roots (doesn't work the other way round!), so there are 3 complex roots.
The mean of the discrete probability distribution is of 1.28.
<h3>What is the mean of a discrete distribution?</h3>
The expected value of a discrete distribution is given by the <u>sum of each outcome multiplied by it's respective probability</u>.
Then, considering the given distribution, the mean is given by:
E(X) = 0(0.13) + 1(0.61) + 2(0.15) + 3(0.07) + 4(0.04) = 1.28.
More can be learned about the mean of a discrete probability distribution at brainly.com/question/24855677
