Answer:
a)0.55
b)0.58
Step-by-step explanation:
a) Lets consider that 100 call received from call center. We expect that 32 of them is from abroad and 38 of them is to make a change to an existing reservation. It normally makes that 70 of 100 call is aboard or to make a change. But there are 15 call is in common. Then we need to subtract this number from total calls:
70-15=55 calls we expecting out of 100 calls that both abroad or to make a change.
and the probability is 0.55
b) If we know that they are independent We can use below formula to find in common calls.
![P(X=x,Y=y)=P(X=x)P(Y=y)\\P(X=x,Y=y)=0.32*0.38\\P(X=x,Y=y)=0.12](https://tex.z-dn.net/?f=P%28X%3Dx%2CY%3Dy%29%3DP%28X%3Dx%29P%28Y%3Dy%29%5C%5CP%28X%3Dx%2CY%3Dy%29%3D0.32%2A0.38%5C%5CP%28X%3Dx%2CY%3Dy%29%3D0.12)
There must be 12 calls in common from out of 100 calls. Now we need to subtract 12 from total calls we expected.
70-12=58 calls we expecting out of 100 calls that both abroad or to make a change.
and the probability is 0.58