Relative frequency · Alberta Grade 6 · maddyhelps.com
Name
Date
A spinner has four equal parts: red, blue, green and yellow. A class spun it 40 times. Write each colour's relative frequency three ways. Then use the coin results to see what more trials do.
Colour
Times
Fraction
Decimal
Percent
Red
12
Blue
9
Green
11
Yellow
8
Each colour is equally likely. What fraction of spins would you expect to be red?
Heads, as a percent of all flips, as the number of flips grows
What happens to the percent of heads as there are more flips — and why?
For the grown-up
How often?
Red: 12/40 = 3/10 = 0.3 = 30%; Blue: 9/40 = 0.225 = 22.5%; Green: 11/40 = 0.275 = 27.5%; Yellow: 8/40 = 1/5 = 0.2 = 20%. Expected: 1/4 of spins red, or 10 of 40. The coin: 7 of 10 = 70%, 12 of 20 = 60%, 27 of 50 = 54%, 52 of 100 = 52%, 104 of 200 = 52%. With more flips the percent settles close to 50%, the expected likelihood — the law of large numbers.
Relative frequency is Grade 6's statistics outcome: a count divided by the total. Twelve reds in forty spins is not a sign the spinner is unfair; the class's small sample just wobbles, which the coin graph shows happening and then settling.