NW 21. On-Time Flights According to American Airlines, Flight 215
from Orlando to Los Angeles is on time 90% of the time.
Randomly select 150 flights and use the normal approximation
to the binomial to
(a) approximate the probability that exactly 130 flights are on
time.
(b) approximate the probability that at least 130 flights are on
time.
(c) approximate the probability that fewer than 125 flights are
on time.
(d) approximate the probability that between 125 and 135
flights, inclusive, are on time.
administered today to 200 randomly selected males between
the ages of 18 and 24 years, and 130 of them respond that they
live at home.
(a) Approximate the probability that such a survey will result
in at least 130 of the respondents living at home under the
assumption that the true percentage is 55%.
(b) What does the result from part (a) suggest?
26. Females Living at Home According to the Current
Population Survey (Internet release date: September 15,
2004), 46% of females between the ages of 18 and 24 years
lived at home in 2003. (Unmarried college students living in a
dorm are counted as living at home.) Suppose a survey is
