A certain flight arrives on time 87 percent of the time. Suppose 180 flights are randomly selected. Use the normal approximation to the binomial to approximate the probability that (a) exactly 167 flights are on time. (b) at least 167 flights are on time. (c) fewer than 154 flights are on time. (d) between 154 and 167, inclusive are on time.

Suppose that a family has seven children. Also, suppose that the probability of having a girl is 1/2. Find the probability that the family has at least six girls.

Assume that when adults with smartphones are randomly selected, 52% use them in meetings or classes. If 25 adult smartphone users are randomly selected, find the probability that exactly 19 of them use their smartphones in meetings or classes. The probability is. (Round to four decimal places as needed.)

Cassandra buys a bag of cookies that contains 4 chocolate chip cookies, 8 peanut butter cookies, 6 sugar cookies and 8 oatmeal cookies. What is the probability that Cassandra reaches in the bag and randomly selects a sugar cookie from the bag, eats it, then reaches back in the bag and randomly selects an oatmeal cookie? Give your answer as a fraction, or accurate to at least 4 decimal places.