Prob & Stats Chapter 14 Review
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4. People with type O-negative blood are universal donors. That is, any
patient can receive a transfusion of O-negative blood. Only 7.2% of the
American population has O-negative blood. If 4 people appear at random to
give blood, what is the probability that at least 1 of them is a universal
donor?
5. Use the table above.
a. What is the probability that a full time student visited the tutoring center
once?
Prob & Stats Chapter 14 Review
b. What is the probability that a part time student visited the center two or
more times?
c. If a student visited the center two to three times, what is the probability
that the student is full time?
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6. Stat students were asked what their favorite meal was. 45% like pizza best,
60% like burgers best, and 20% cannot decide between the two so they like
both. Draw a Venn diagram and calculate the following:
a. The probability that a randomly selected Stat student likes pizza OR
burgers?
a. The probability that a randomly selected Stat student likes pizza AND
burgers?
b. The probability that a randomly selected Stat student likes pizza OR
burgers, BUT NOT BOTH?
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7. Are the following events independent or dependent? EXPLAIN!
P(A)= 0.4 P(B)= 0.6
P(A∩B)=0.24
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8. Suppose that PA took a survey of 350 college students who graduated
within the last four years. Each student is asked the type of college attended
(public or private) and the family’s income level (low, middle, high). Use the
table below to answer the questions. Express probabilities as simplified
fractions.
Public
Private
Total
Low
120
20
140
Middle
110
50
160
High
22
28
50
Prob & Stats Chapter 14 Review
Total
252
98
350
Find the probability of randomly selecting a student who
a)
b)
c)
d)
is not from a high-income family.
attends a private college.
is from a high-income family or a public college.
attends a private college and is from a middle-income family.
9. Ethan is trying to decide what to wear on his first day back to school. He
has to choose either blue, black or grey sweatpants. He has a PA t-shirt, a
Yankees t-shirt, and a “Mrs. Cocco is the best” t-shirt. Please draw a tree
diagram of all possible outfits and determine the probability that Ethan
chooses grey sweatpants and the “Mrs. Cocco is the best” shirt.
10. You pick 3 cards at random from a deck. What is the probability of each
below:
a. You get no Kings.
b. You get all spades.
c. You have to wait until the last card to draw a red card.
d. You get at least one club.
11. Make a tree diagram to answer the following. Students at PAHS need to
decide if they are returning to in-person learning. Of those surveyed, 72%
students plan on returning. Of those returning, 24% say they are planning on
using their own laptop. Of those remaining all virtual, 68% say they will use
their school chrome books. What is the probability that a randomly selected
student is in-person and uses a school chrome book? What is the probability
that a randomly selected chrome book user is in-person? (Note: this is asking
what is the probability that a student is in-person, GIVEN they are using a
chrome book user.)