Problem 17.17: If you flip a fair coin 100 times,
a) Intuitively, how many heads do you expect?
b) Use the formula for expected value to verify your intuition.
Problem 17.19: Assume that 13% of people are left handed. If we select five
people at random, find the probability of each outcome described below.
a) The first lefty is the fifth person chosen.
b) There are some lefties among the five people.
c) The first lefty is the second or third person.
d) There are exactly three lefties in the group.
e) There are at least three lefties in the group.
f) There are no more than three lefties in the group.
Problem 17.23: Suppose we choose 12 people instead of the five chosen in
a) Find the mean and standard deviation of the number of right-handers in the
b) What is the probability that they’re not all right-handed?
c) What is the probability that there are no more than 10 rightists?
d) What is the probability that there are exactly six of each?
e) What is the probability that the majority is right-handed?
Problem 17.25: It is generally believed that nearsightedness affects about 12% of
all children. A school district tests the vision of 169 incoming kindergarten
children. How many would you expect to be nearsighted? With what standard
Problem 17.27: A certain tennis player makes a successful first service 70% of
the time. Assume that each serve is independent of the others. If she serves six
times, what is the probabilit