Mr. and Mrs. Doran have a genetic history such that the probability that a child being born to them with a certain trait is 0.41 . If they have six children, what is the probability that at least four of their six children will have that trait? Round your answer to the nearest thousandth.Answer:
Q. Mr. and Mrs. Doran have a genetic history such that the probability that a child being born to them with a certain trait is 0.41 . If they have six children, what is the probability that at least four of their six children will have that trait? Round your answer to the nearest thousandth.Answer:
Identify values n, k, p: Identify the values of n, k, and p for the binomial probability formula.n=6 (the number of children)p=0.41 (the probability of a child having the trait)We want to find the probability of at least k=4 children having the trait, which means we need to calculate the probabilities for k=4, k0, and k1 and sum them up.
Use binomial probability formula: Use the binomial probability formula P(X=k)=C(n,k)⋅(p)k⋅(1−p)(n−k) to calculate the probability for k=4.P(X=4)=C(6,4)⋅(0.41)4⋅(1−0.41)(6−4)
Calculate C(6,4): Calculate the binomial coefficient C(6,4).C(6,4)=4!(6−4)!6!= (4×3×2×1×2×1)(6×5×4×3×2×1)= 26×5= 15
Multiply values for P(X=4): Multiply the values together to find P(X=4).P(X=4)=15×0.0282401×0.3481=0.147651615
Repeat for k=5 and k=6: Repeat the process for k=5 and k=6. First, calculate P(X=5) using the binomial probability formula. P(X=5)=C(6,5)⋅(0.41)5⋅(1−0.41)6−5
Calculate C(6,5): Calculate the binomial coefficient C(6,5).C(6,5)=5!(6−5)!6!=6
Multiply values for P(X=6): Multiply the values together to find P(X=6).P(X=6)=1×0.004665641×1=0.004665641
Sum probabilities for at least 4: Sum the probabilities P(X=4), P(X=5), and P(X=6) to find the total probability of at least four children having the trait.P(at least 4)=P(X=4)+P(X=5)+P(X=6)=0.147651615+0.040930806+0.004665641=0.193248062
Round final probability: Round the final probability to the nearest thousandth. P(at least 4)=0.193
More problems from Find probabilities using the binomial distribution