Probability Vocabulary

Probability Kelly is playing a game using 8 number cards numbered 1-8. Kelly scores a point if she selects a card that has a 7 or greater. 1 2 3 4 5 6 7 8

Probability Experiment Probability experiment- an experiment where the exact results cannot be predicted. Example: Blindly selecting cards in Kelly’s game

Outcome- a possible result in a probability experiment. Example: Any of the numbers (1-8) on the cards in Kelly’s game.

Sample Space Sample space- a set of all possible outcomes in a probability experiment. Example: A sample space for this experiment is 1, 2, 3, 4, 5, 6, 7, & 8 (the numbers on the card).

Event- a set of one or more outcomes in a probability experiment. Example: Selecting an even number or selecting a specific number.

Probability Probability- a number greater than or equal to 0 and less than or equal to 1, showing the chance of an event happening. The probability (P) of an event (A) is… Number of favorable outcomes P(A) = Number of possible outcomes Example: Kelly is hoping to select a 7 or greater. This means the favorable outcomes are selecting a 7 or 8. Possible outcomes are 1, 2, 3, 4, 5, 6, 7, or 8 Selecting a 7 or 8 2 1 P(7 or greater) = = = Number of possible outcomes 8 4

Likely- an event will probably happen. Since there are 4 blue sections and only 1 red section, it is likely that this spinner will land on blue.

Spinning a yellow or a green are equally likely. Equally Likely- an event that is just as likely to happen as not to happen. Spinning a yellow or a green are equally likely.

Unlikely Unlikely- an event that probably will not happen. Since green is only 1 of 11 sections, spinning a green is unlikely.

Impossible Impossible- an event that cannot happen. The possibility of spinning a yellow is impossible.

Certain Certain- an event will definitely happen. The possibility of spinning a blue is certain.

P(purple) Probability Ratio Fraction Decimal Percent 1:8 ⅛ 0.125 12.5% Probability can be expressed in four different ways: ratio, fraction, decimal, & percent. 1 2 3 4 8 7 6 5 P(purple) Ratio Fraction Decimal Percent 1:8 ⅛ 0.125 12.5%

P(4 or 5) Probability Ratio Fraction Decimal Percent 2:8 ¼ 0.25 25% Probability can be expressed in four different ways: ratio, fraction, decimal, & percent. 1 2 3 4 8 7 6 5 P(4 or 5) Ratio Fraction Decimal Percent 2:8 ¼ 0.25 25%

P(even #) Probability Ratio Fraction Decimal Percent 4:8 ½ 0.5 50% Probability can be expressed in four different ways: ratio, fraction, decimal, & percent. 1 2 3 4 8 7 6 5 P(even #) Ratio Fraction Decimal Percent 4:8 ½ 0.5 50%

P(# greater than 3) Probability Ratio Fraction Decimal Percent 5:8 ⅝ Probability can be expressed in four different ways: ratio, fraction, decimal, & percent. 1 2 3 4 8 7 6 5 P(# greater than 3) Ratio Fraction Decimal Percent 5:8 ⅝ 0.625 62.5%

P(blue shirt) Probability Ratio Fraction Decimal Percent 8:20 0.40 40% Probability can be expressed in four different ways: ratio, fraction, decimal, & percent. Paul’s Closet Color # of Shirts Green 3 Red 4 White 5 Blue 8 Total 20 P(blue shirt) Ratio Fraction Decimal Percent 8:20 2 5 0.40 40%

P(green or red) Probability Ratio Fraction Decimal Percent 7:20 0.35 Probability can be expressed in four different ways: ratio, fraction, decimal, & percent. Paul’s Closet Color # of Shirts Green 3 Red 4 White 5 Blue 8 Total 20 P(green or red) Ratio Fraction Decimal Percent 7:20 7 20 0.35 35%

Probability P(any color, but white) Ratio Fraction Decimal Percent Probability can be expressed in four different ways: ratio, fraction, decimal, & percent. Paul’s Closet Color # of Shirts Green 3 Red 4 White 5 Blue 8 Total 20 P(any color, but white) Ratio Fraction Decimal Percent 15:20 ¾ 0.75 75%

P(pink) Probability Ratio Fraction Decimal Percent 0:20 0.00 0% Probability can be expressed in four different ways: ratio, fraction, decimal, & percent. Paul’s Closet Color # of Shirts Green 3 Red 4 White 5 Blue 8 Total 20 P(pink) Ratio Fraction Decimal Percent 0:20 20 0.00 0%