Question

How do you do the following statistics problem, I can use a Ti-84:

1. 50 percent of all marriages end in divorce during the first five years of marriage. The probability that the number of marries couples in a group of 50 couples, still living together after five years of marriage is at least 25 is...

The answer is 0.556

Answer 1

Ans:

Use binomial distribution with n=50 and p=0.5

P(x>=25)=1-P(x<=24)

=1-binomcdf(50,0.5,24)

=1-0.444

=0.556

P(X Sc) binomedf (n, p,c) n->number of trials p -> probability of success This finds the probability of c or fewer successes.