Page 249 - Probability Demystified

238 FINAL EXAM

37. A survey found that one in five Americans say that he or she has
visited a doctor in any given month. If 10 people are selected at
random, the probability that exactly 3 visited a doctor last month is
a. 0.101
b. 0.201
c. 0.060
d. 0.304
38. A survey found that 30% of teenage consumers received their
spending money from a part time job. If 5 teenagers are selected at
random, the probability that 3 of them have income from a part time
job is
a. 0.132
b. 0.471
c. 0.568
d. 0.623

39. A box contains 4 white balls, 3 red balls, and 3 blue balls. A ball is
selected at random and its color is noted. It is replaced and another
ball is selected. If 5 balls are selected, the probability that 2 are white,
2 are red, and 1 is blue is
72
a.
365
41
b.
236
52
c.
791
1
d.
14

40. If there are 200 typographical errors randomly distributed in a 500-
page manuscript, the probability that a given page contains exactly
3 errors is

a. 0.0063
b. 0.0028
c. 0.0072
d. 0.0014