Remarkable / Worksheets / Grade 7 Maths / Probability
A one-page CAPS Grade 7 Maths poster on probability (Data), with the key ideas, key words and a tip to remember.
Probability tells us how likely an event is. It is a number from 0 to 1.
P(event) = number of ways the event can happen ÷ total number of equally likely outcomes.
Spinner: 3 red, 2 blue, 1 green
P(blue) = 26 = 13
Do an experiment. Relative frequency = number of times it happened ÷ number of trials. More trials give a better estimate.
A coin is tossed 40 times: 18 heads.
1840 = 920 = 0,45 = 45%
Add the probabilities of an event happening and not happening to get 1.
P(win) = 25
P(not win) = 1 − 25 = 35
Expected number = probability × number of trials.
P(landing on red) = 14
In 80 spins: 14 × 80 = 20 times