6. Before 1918, approximately 60% of the wolves in a region were male, and 40% were female. However, cattle ranchers in

[answerhappygod]

6. Before 1918, approximately 60% of the wolves in a
region were male, and 40% were female. However, cattle
ranchers in this area have made a determined effort to exterminate
wolves. From 1918 to the present, approximately 70% of
wolves in the region are male, and 30% are female.
Biologists suspect that male wolves are more likely than females to
return to an area where the population has been greatly reduced.
(Round your answers to three decimal places.)
(a) Before 1918, in a random sample of 10 wolves
spotted in the region, what is the probability that 7 or
more were male?


What is the probability that 7 or more were female?


What is the probability that fewer than 4 were
female?

(b) For the period from 1918 to the present, in a random sample
of 10 wolves spotted in the region, what is the
probability that 7 or more were male?


What is the probability that 7 or more were female

What is the probability that fewer than 4 were
female?
7. The one-time fling! Have you ever purchased an article of
clothing (dress, sports jacket, etc.), worn the
item once to a party, and then returned the
purchase? This is called a one-time fling.
About 15% of all adults deliberately do a one-time fling
and feel no guilt about it! In a group of ten adult
friends, what is the probability of the following? (Round your
answers to three decimal places.)
(a) no one has done a one-time fling


(b) at least one person has done a one-time fling


(c) no more than two people have done a one-time fling
13. Do you tailgate the car in front of you?
About 30% of all drivers will tailgate before passing,
thinking they can make the car in front of them go faster. Suppose
that you are driving a considerable distance on a two-lane highway
and are passed by 10 vehicles.
(a) Let r be the number of vehicles that
tailgate before passing. Make a histogram showing the probability
distribution of r for r =
0 through r = 10.
(b) Compute the expected number of vehicles out
of 10 that will tailgate. vehicles

(c) Compute the standard deviation of this distribution. (Round
your answer to two decimal places.) vehicles
14. The Denver Post reported that, on
average, a large shopping center had an incident of shoplifting
caught by security 2.2 times every six hours.
The shopping center is open from 10 A.M. to 9
P.M. (11 hours). Let r be the number
of shoplifting incidents caught by security in
an 11-hour period during which the center is open.
(a) Explain why the Poisson probability distribution would be a
good choice for the random variable r.
Frequency of shoplifting is a rare
occurrence. It is reasonable to assume the events are
independent.
Frequency of shoplifting is a common
occurrence. It is reasonable to assume the events are
independent.
Frequency of shoplifting is a common
occurrence. It is reasonable to assume the events are
dependent.
Frequency of shoplifting is a rare
occurrence. It is reasonable to assume the events are
dependent.
What is 𝜆? (Round your answer to three decimal places.)

(b) What is the probability that from 10 A.M. to 9 P.M. there will
be at least one shoplifting incident caught by security? (Round
your answer to four decimal places.)


(c) What is the probability that from 10 A.M. to 9 P.M. there will
be at least three shoplifting incidents caught by security? (Round
your answer to four decimal places.)


(d) What is the probability that from 10 A.M. to 9 P.M. there will
be no shoplifting incidents caught by security? (Round your answer
to four decimal places.)
15. USA Today reported that Parkfield, California, is
dubbed the world's earthquake capital because it sits on top of the
notorious San Andreas fault. Since 1857, Parkfield has had a major
earthquake on the average of 1.4 times every 22
years.
(a) Explain why a Poisson probability distribution would be a
good choice for r = number of earthquakes in a
given time interval.
Frequency of earthquakes is a common occurrence. It is
reasonable to assume the events are dependent.
Frequency of earthquakes is a rare occurrence. It is
reasonable to assume the events are
dependent.
Frequency of earthquakes is a common occurrence. It is
reasonable to assume the events are independent.
Frequency of earthquakes is a rare occurrence. It is
reasonable to assume the events are independent.
(b) Compute the probability of at least one major earthquake in the
next 22 years. Round 𝜆 to the nearest hundredth, and use
a calculator. (Use 4 decimal places.)


(c) Compute the probability that there will be no major earthquake
in the next 22 years. Round 𝜆 to the nearest hundredth,
and use a calculator. (Use 4 decimal places.)

(d) Compute the probability of at least one major earthquake in the
next 47 years. Round 𝜆 to the nearest
hundredth, and use a calculator. (Use 4 decimal places.)


(e) Compute the probability of no major earthquakes in the
next 47 years. Round 𝜆 to the nearest
hundredth, and use a calculator. (Use 4 decimal places.)