The following table contains the probability distribution for X = the number of retransmissions necessary to successfully transmit a 1024K data package through a double satellite media.
X
0
1
2
3
P(X)
0.35
0.25
***
0.15
The mean or expected value for the number of retransmissions is?
To find the expected value, we can multiply each value of X by its corresponding probability and then sum up the results.
Expected value = E(X) = 0(0.35) + 1(0.25) + 2(unknown) + 3(0.15)
0.35 + 0.25 + unknown + 0.45 = 1
0.6 + unknown = 1
unknown = 0.4
Therefore, the mean or expected value for the number of retransmissions is 0.4.