Grade 8 · Math · Unit 8 of 8
Probability & Data
Chance, mean, median and mode
What your child practises
Counting outcomes, finding theoretical and experimental probabilities, predicting how often something will happen, and summarizing data with the mean, median and range.
BC Curriculum learning standard: Theoretical probability; central tendency: mean, median and mode
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
A shop sells 2 kinds of shirts and 6 kinds of pants. How many different outfits can you make with one of each?
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12
Hint: Multiply the choices: 2 × 6 = 12.
Question 2
A bag has 1 red, 3 blue and 6 green marbles. What is the probability of picking a blue marble? Type it as a fraction in lowest terms.
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3/10
Hint: P(blue) = favourable ÷ total = 3/10, which is 3/10 in lowest terms.
Question 3
A bag has 1 red, 3 blue and 6 green marbles. What is the probability of NOT picking blue? Type a fraction in lowest terms.
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7/10
Hint: Not blue means red or green: 1 + 6 = 7 marbles out of 10. That is 7/10. (Or 1 − 3/10.)
Question 4
Sam spins a spinner 40 times and it lands on green 33 times. What is the experimental probability of green? Type a fraction in lowest terms.
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33/40
Hint: Experimental probability = successes ÷ trials = 33/40 = 33/40.
Question 5
A spinner lands on blue with probability 1/2. About how many blue spins do you expect in 16 spins?
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8
Hint: Expected number = probability × trials = 1/2 × 16 = 8.
Question 6
What is the median of 11, 6, 8, 12, 17?
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11
Hint: Put them in order: 6, 8, 11, 12, 17. The middle number is 11.