math
posted by m .
Four welldefined social classes (1=low and 4=high) exist in a country. If X is a random variable giving the social class of the son of a father from social class 1, the distribution of X is as follows:
we have a small chart that has son's class, X and a 1,2,3,4 next to it then beneath it there is Probability of son's class (below Sons class and X) and beneath 1 is 0.52, beneath 2 is 0.26, beneath 3 is 0.18 and beneath 4 is 0.04.
Does this probability distribution for X appear to be reasonable? What is the probability that X takes on a value less than or equal to 3?

I was hoping that this question was answered... It's Greek to me!