Ratios are statements of comparisons of two quantities.
Proportions are equations showing that two ratios are equivalent.
Probability
 Is the chance of an event happening.
 If a particular outcome can never occur, its probability is 0.
 If an outcome is certain to occur, its probability is 1.
 In general, if p is the probability that a specific outcome will occur, values of p fall in the range 0 <= p <= 1.
 Probability may be expressed as either a decimal, a fraction, or a ratio.
 Probability examples in everyday life include weather prediction, board games, sports statistics, etc.
Examples:
What are the chances that the sun will shine this month? (likely)
What are the chances that you, a 11 year old boy, will be driving a car today? (unlikely)
What are the chances of tossing heads or tails on a coin? (equally likely)
Coin: 2 sides
The probability of rolling heads is 1/2
The probability of rolling tails is 1/2
Cube: 6 sides
Take a number cube and label the sides 1  6.
The probability of rolling a 3 is one outcome out of a total of six possible outcomes, that is 1/6.
Similarly, the probability of rolling a 5 is also 1/6.
The probability of rolling an odd number (1, 3, 5) = three outcomes out of a total of six possible outcomes = 3/6 = 1/2
Probability of rolling an even number is also same as rolling an odd numbers (3/6 or 1/2).
To help you understand or learn about finding the probability of two or more events, make a letter cube using one of your number cubes (for example, 1 equals the letter a, 2 equals the letter b, 3 equals the letter c, and so on). Roll one cube and one letter cube.
Probability of two or more events: first find the probability of each event and then multiply the two probabilities to find the probability of both events occurring together.
Example: Rolling a 4 and letter c has a probability of 1/6 (rolling a 4) x 1/6 (rolling a letter c) = 1/36.
The probability would be the same for rolling a 2 and rolling a letter e.
To find the probability of the above two events, multiply 1/36 x 1/36 which equals 1/1296
Directions: Solve the following problems. Show your work on a sheet of paper. Also write at least 5 examples of your own.
