HELP ME SOLVE THIS

Question

The table to the right lists probabilities for the corresponding numbers of girls in three births. What is the random variable, what are its possible values, and are its values numerical?
Number of girls

x   P(x) 

0   0.125
1   0375

Answer 1

1/8 chance of zero girls in 3 tries = (1/2)^3 = .5^3 = .125 = 12.5% chance

3/8 chance of one girl in 3 tries = .375 = 37.5% probability

50% chance of 2 or 3 girls in 3 tries

random variable is number of girls in 3 tries: either 0, 1, 2 or 3

P(3) = 12.5% = P(1)

P(4) = 37.5% = P(2)