Probability Probability Probability is the likelihood or chance
Probability
Probability � Probability is the likelihood or chance of an event occurring � Probability can be calculated by: Favourable outcomes Possible outcomes Probabilities can be expressed as percents, ratios or fractions
Example #1 �A spinner is divided into 5 equal sections. The spinner is spun once. Find the following probabilities. Write each as a fraction, ratio and percent. � a) prob. of orange � b) prob. of green and yellow
Solution � a) There are five possible outcomes: red, orange, green, yellow and purple � There is only one favourable outcome orange P(orange) = favourable outcomes/possible out. P(orange) = 1/5 = 1: 5 = 20%
Solution � b) There are five possible outcomes: red, orange, green, yellow and purple There are two favourable outcomes – green and yellow P(grn + yel) = favourable outcomes/possible out. P(grn + yel) = 2/5 = 2: 5 = 40%
Independent Events � Independent events = the outcome of one event has no affect on the outcome of another event � Example: if you rolled a dice you might end up with a 4. If you rolled the dice again, the first 4 would not affect the next roll. You could roll any of the six possible numbers.
Dependent Events � Dependent events = the outcome of one event affects the outcome of a second event. Example: If you drew a card from a deck you would have a 1/52 chance of choosing that card. If you did NOT replace that card and drew another, the chance of getting any one card would now be 1/51. Sample Space = all possible outcomes of an experiment
Bookwork �Grade �Page 7 textbook 163 # 3, 4, 5, 6, 7, 8, 9
- Slides: 8