Presentation on theme: "Everything you need to know about in grade 6 Probability."— Presentation transcript:
Everything you need to know about in grade 6 Probability
Probability (The chance of something happening) Certain (100% sure it will happen) Impossible (100% sure it will not happen) Possible (It may or may not happen) Likely (Large chance it will happen) Unlikely (Small chance it will happen)
There are 2 kinds of probability experimentalprobability theoreticalprobability
ExperimentalProbability (Based on the results of an experiment) For example: When rolling a die five times, what is the experimental probability of getting a six? Out of my 5 tests, I rolled a six twice So, in this case… the experimental probability of getting a six is 2 or 40% 5
TheoreticalProbability (Based on all the possible outcomes) For example: When rolling a die, what is the theoretical probability of getting a six? Rolling a 6 is one out of six possible outcomes So… The theoretical probability of getting a six is 16
TheoreticalProbability We can also determine all possible outcomes in situations with multiple factors.
For example: When I go out for dinner with my family, I get to order an appetizer, main dish, and dessert. The appetizers on tonights menu are garden salad or mushroom soup. The main dishes are beef stew, lasagna, or grilled chicken. The desserts are fruit salad or sorbet. List all the possible meal combinations.
I can lay out all my options in a TREE DIAGRAM I will list my appetizer options first. GardenSalad MushroomSoup Next, I will list my main dish options. Beef Stew Lasagna Grilled Chicken Beef Stew Lasagna Grilled Chicken Last, I will list my dessert options. Fruit Salad Sorbet Sorbet Sorbet Sorbet Sorbet Sorbet I can follow the branches of my diagram to see all my possible combinations. I count 12 possible choices. I can count the items in the right column to know the amount of choices I have.
If all I wanted to know was how many possible combinations there were, I could have created a table AppetizersMain DishesDesserts Garden Salad Beef StewFruit Salad Mushroom Soup LasagnaSorbet Grilled Chicken I could then multiply together the amount of choices in each category to determine the total number of possible combinations 2choices 3choices 2choices X X 2 x 3 x 2 = 12 There are 12 possible choices
Lets see if you can answer some probability questions… If Sam flipped a coin ten times, how many times would you expect him to get heads? Right! You would expect him to get heads 5 times, because the theoretical probability of getting heads is 1/2 and 5/10 = 1/2 Sam actually only got heads once Did he do anything wrong? No he didnt! Experimental probability can be different from theoretical probability. Even though it is unlikely that Sam would only get heads once, it is still possible.
Lets see if you can answer some probability questions… We surveyed our class to find out about ice cream preferences. 12 preferred vanilla 8 preferred chocolate 5 didnt like ice cream at all. Each student writes his/her name on a slip of paper and puts it in a bag. What are the chances of drawing the name of a student who prefers chocolate ice cream? 8/25 or 32%