Running Head: PROBABILITY
1
1.
During a recent survey of ethnic backgrounds of 1000 people in a large city, 513 were
Canadian, 148 were French, 72 were African and 56 were Asian and the remainder
were from other groups.
Calculate the probability that a person, selected at random from the population has:
a.
a Canadian background?
=
513
1000
= 0.513
= 51.3%
b.
an African background?
=
72
1000
= 0.072
= 7.2%
c.
an “other” background?
513+148+72+56
= 789
1000-789
= 211
=
211
1000
= 0.211
= 21.1%
6 marks
2.
A spinner is divided into three equally sized regions as shown. The spinner is spun
twice. For each probability you determine, express your answer as a fraction, decimal

PROBABILITY
2
and percent.
a.
What is the probability of spinning A on the first spin?
100
÷
3= 33.3%
P(A)=
1
3
= 0.3
= 33.3%
b.
Draw a tree diagram to represent the sample space for both spins.
c.
What is the probability of spinning A followed by B?
P(AB)=
2
9
= 0.22
= 22.2%
d.
What is the probability of getting the same letter on both spins?
P(AA,BB,BB,BB,BB)=
5
9

PROBABILITY
3
= 0.55
= 55.5%
6 marks
3.
We have looked in detail at three probability distributions;
a.
Binomial
b.
Geometric
c.
Hypergeometric
For each one,
i.
Explain the conditions in which we would use it.
a.
Binomial is used when events have a fixed number of trials and a fixed probability of
success. Events are also independent.
b.
Geometric is used when events have a fixed probability of success but not a fixed
number of trials. Like binomial, events are independent.
c.
Hypergeometric is used when events have a fixed number from a finite pool. Unlike
binomial and geometric, hypergeometric events are dependent.

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- Summer '17
- Statistics, Remainder, Probability, Probability theory, Binomial distribution, Negative binomial distribution, Hypergeometric Distribution, C. Hypergeometric