Answer:I cannot see photo
The answer is simplified to 15
For any distribution, the sum of the probabilities of all possible outcomes must be 1. In this case, we have to have
We're told that 
, and we're given other probabilities, so we have
The expected number of calls would be
![E[X]=\displaystyle\sum_xx\,P(X=x)](https://tex.z-dn.net/?f=E%5BX%5D%3D%5Cdisplaystyle%5Csum_xx%5C%2CP%28X%3Dx%29)
![E[X]=0\,P(X=0)+1\,P(X=1)+\cdots+4\,P(X=4)](https://tex.z-dn.net/?f=E%5BX%5D%3D0%5C%2CP%28X%3D0%29%2B1%5C%2CP%28X%3D1%29%2B%5Ccdots%2B4%5C%2CP%28X%3D4%29)
![E[X]=1.4](https://tex.z-dn.net/?f=E%5BX%5D%3D1.4)
Answer:
C. 1 inch = 23 miles
Step-by-step explanation:
To find the scale, add the scale distances shown first.
2.25 + 1.75 = 4 inches on the map
Now, divide the actual mileage (92 miles) by how long it was on the map.
92 / 4
92 = 80 + 12
92/4 = (80/4) + (12/4)
92/4 = 20 + 3
92/4 = 23 miles
That means 1 inch on this map is actually 23 miles. So the scale of the map is 1 inch = 23 miles, which is C.
