Grade 9 · Math · Unit 11 of 11
Probability in Society
Chance, fair games, forecasts and risk.
What your child practises
Practises how probability is used in everyday life: forecasts, fair games and expected value, insurance, independent events and experimental versus theoretical probability.
Manitoba Curriculum learning outcome: 9.SP.4 · the role of probability in society
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Flipping a coin 10 times gives 7 heads. What is this result called?
- a sample space
- the theoretical probability
- an experimental result
an experimental result
Hint: It comes from doing the experiment.
Question 2
A coin lands heads five times in a row. What is the chance of heads on the next flip?
- less than 1/2
- 1/2
- more than 1/2
1/2
Hint: Each flip is independent. The coin has no memory.
Question 3
As you repeat an experiment many more times, the experimental probability usually gets…
- equal to zero
- further from it
- closer to the theoretical probability
closer to the theoretical probability
Hint: This is the law of large numbers.
Question 4
Why do insurance companies use probability?
- to avoid paying anyone
- to estimate how often claims will happen so they can set prices
- to decide which houses will burn
to estimate how often claims will happen so they can set prices
Hint: They look at large groups of people over many years.
Question 5
A probability of 0 means the event is…
- unlikely
- impossible
- certain
impossible
Hint: 0 is the lowest probability.
Question 6
In the raffle above, a ticket costs $2 and is worth $1 on average. Over many tickets, a player will…
- lose money on average
- win money on average
- break even exactly
lose money on average
Hint: The average prize is less than the cost.