The one that is like this:^
Answer:

Step-by-step explanation:
Number of students participating in the competition = 13.
Total number of students in the school = 15.
Thus ,
the number of students who did not make to this competition =
Total number of students - number of students participated
= 15-13 = 2.
Now ,
probability of the student who do not makes it to the competition
= fraction of students who did not make to this competition from the total number of students .
=
.
I think you are looking for a percentage but it works be about 266% or 2.66 books per month
Solution: We are given:

We need to find the z value corresponding to probability 0.84, in order to find the how much money almost 84% of gamblers spent at casino.
Using the standard normal table, we have:

Now we will use the z score formula to find the required amount:





approximately
Therefore, almost 84% of gamblers spent more than $720 amount of money at this casino.