The Jones family was one of the first to come to the U. S. They had 4 children. Assuming that the probability of a child being a girl is .5, find the probability that the Jones family had:.
(a) at least 3 girls
(b) at most 3 girls

a) The probability that the Jones family had at least 3 girls is 0.3125.

b) The probability that the Jones family had at most 3 girls is 0.9375.

Explanation:

The probability that the Jones family had at least 3 girls is obtained below:

From the given information, let X be the number of girls follows binomial distribution with number of trails 4 and probability of success is 0.5. Jones having four children. The 0.5 probability that having girl.That is,  and p=0.50The probability mass function of X is ; P (X = x) = 4Cx X (0.5)^x X  (1 - 0.5)^4-x

a) P(At least 3 girls) = P(3 girls) + P(4 girls)

= 4C3 x (0.5)^3 x (0.5)^1 + (0.5)^4

= 0.3125 is the probability that the Jones family had at least 3 girls

b) at most 3 girls ; The probability that the Jones family had at most 3 girls is obtained below:

From the given information, let X be the number of girls follows binomial distribution with number of trails 4 and probability of success is 0.5.  and .The probability mass function of X is, P (X = x) = 4Cx X (0.5)^x X  (1 - 0.5)^4-xThe required probability is P(x<=3) = 1 - P(X>3) = 1 - P(X = 4)= 1 - 0.0625

The probability that the Jones family had at most 3 girls is 0.9375.

It’s either d or b ! but it might be b

Smelly rocks sink in water haha!