Page 91 - Algebra 1

Chance, like probability, is the likelihood of an event occurring.
Example
3
Calculating Chance
In a bucket there are 10 balls numbered as follows: 1, 1, 2, 3, 4, 4, 4, 5, 6, and 6. A single ball is randomly chosen from the bucket. What is the probability of drawing a ball with a number greater than 4? Is there a greater chance of drawing a number greater than 4 or a 1?
SOLUTION
P(greater than 4) = _3 3 out of the 10 balls have a number greater than 4. 10
The probability of drawing a ball with a number greater than 4 is 0.3, or 30%.
P(1)=_2 =_1 10 5
_3 >_1 10 5
2outofthe10ballsarenumbered1.
Compare_3 and_1. 10 5
There is a greater chance of drawing a number greater than 4 than drawing a 1.
Application: State Fair
At a carnival game, you drop a ball into the top of the device shown below. As the ball falls, it goes either left or right as it hits each peg. In total, the ball can follow 16 different paths. The ball eventually lands in one of the bins at the bottom and you win that amount of money. (One path to $0 is shown.) What is the probability of winning $2?
Example
4
Math Reasoning
Analyze If you drop the ball once, is there less than or greater than a 20% probability of not winning $2?
SOLUTION
total number of paths = 16
total number of paths to win 16
P($2) = _1 8
The probability of winning $2 is _1 . 8
number of paths to $2 bins = 2
P($2) = number of paths to $2 bins = _ _ _ _2

Lesson Practice
76 Saxon Algebra 1
A number cube labeled 1–6 is rolled. List the outcome for each event.
(Ex 1)
a. a number less than or equal to 4 b. an even number
c. a number greater than 2
There are 4 green, 3 blue, and 3 red marbles in a bag.
(Ex 2)
d. What is the probability of randomly choosing a blue marble?
e. What is the probability of randomly not choosing a red marble?