Besides the obvious one(81*1), the only 2 combinations are 9 and 9, or 27 and 3.
Cos x = 15÷17
because cos is adjacent side over hypotenuse.
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.