Answer:
0.903.
Step-by-step explanation:
Okay, from the question we are given the following information or data or parameters:
''couple plans to have no more than three children, and they will keep having children until they have a girl. So, if their first child is a girl, they will stop and have only one child"
Additionally, from the question we are given that; ''However, if their first child is a boy, they will try again and have a second child".
Also, the probability distribution is given as Boys 0, boys 1 , boy 2, boys 3 boys with Probability 0.490, 0.250, 0.127, 0.133 respectively.
That is, we now have:
Number of boys × probability.
Boys 0 = 0 × 0.490 = 0.
Boys 1 = 1 × 0.250 = 0.250.
Boys 2 = 2 × 0.127 = 0.254.
Boys 3 = 3 × 0.133 = 0.399.
The addition of the products for each Number of boys × probability gives us the expected value. That is to say;
0 + 0.250 + 0.254 + 0.399 = 0.903 = mean.
