Name: __________________
QMTH 205 – Discrete Probability Distributions
1.
The family members living in the Smith household are: Jada (43), Joe (43), Taj (16), Raj (16), Macy (14), and Gracie (13). One of
the family members is randomly selected.
a) Create a probability distribution for the age of the selected family member.
b) Find the expected value for the age of the selected family member.
2.
A local animal shelter currently houses 16 dogs and 8 cats. A group of 4 animals is randomly selected for a feature on the local
cable news channel.
a) Create a probability distribution for the number of dogs that will be in the featured group.
b) Find the expected number of dogs in the featured group.
3.
3/10 of Americans over the age of 25 have a Bachelor’s degree. A random sample of 5 Americans over the age 25 is created.
a) Create a probability distribution for the number of people in the sample who have a Bachelor’s degree.
b) Find the expected number of people in the sample who will have a Bachelor’s degree.
4.
In a shipment of 300 light bulbs, 15 of the bulbs are defective. Find the probability that a random sample of 5 light bulbs
contains:
a) exactly one defective light bulb
b) at least one defective light bulb.
5.
A call center averages 3 calls in any 15 minute period, and calls are independent events. Find the probability that the call center
receives more than one call between 4:35pm and 4:50pm this afternoon.
6.
81% of Americans live in urban areas and 19% live in rural areas. Twenty Americans are randomly selected. Find the probability
that:
a) exactly two of them live in rural areas.
b) exactly eight of them live in urban areas.
c)
7.
at least one of them lives in a rural area.
There are 100 students at a cultural event. 81 of the students are from urban areas. If 20 of the students are randomly selected,
find the probability that:
a) exactly two of them live in rural areas.
b) exactly eight of them live in urban areas.
c)
at least one of them lives in a rural area.