Answer:
0.78
Step-by-step explanation:
"The probability that a family with 5 children will have at least 2 boys" is equivalent to the complement 1 - P(family will have 1 or 0 boys).
We can use a calculator with statistical functions built in to calculate this probability. The function needed is for binomial probability: binom(n, p, x).
P(family will have 1 or 0 boys) = binomcdf(5, 0.5, {0, 1} ) produces two results: one the probab. of having 0 boys and one the probab. of having 1 boy: 0.03125 and 0.1875. We add these together, obtaining 0.21875.
Then we subtract this result from 1 to obtain The probability that a family with 5 children will have at least 2 boys: 1 - 0.21875 = 0.78125, which may be reasonably rounded off to 0.78.
Answer:
81.3%.
Step-by-step explanation:
This is Binomial probability.
Prob( Getting 1 boy) = 5C1 (1/2)^5
= 0.156
Prob ( Getting all girls = 5C5 (1/2)^5
= .031.
So Prob( at least 2 boys = 1 - (0.156 + 0.031)
= 0.813
= 81.3%.
