If the table below represents a probability model based on observed frequencies, what is the value of x
?
Y C A R E S
P(Y) 0.25 0.18 0.30 0.17 x
The sum of all probabilities in a probability model must equal 1. Therefore, we can calculate the value of x by summing the probabilities of Y, C, A, R, and E and subtracting that from 1:
0.25 + 0.18 + 0.30 + 0.17 + x = 1
0.90 + x = 1
x = 1 - 0.90
x = 0.10
Therefore, the value of x in the probability model is 0.10.