Probability
Probability is the measure of how likely an event is to occur. It is expressed as a number between 0 and 1. Probabilities can be impossible, unlikely, somewhat likely, unlikely, highly likely, or certain.
A fish tank has 40 orange fish, 4 blue fish, and 6 black fish. A fish is chosen from the tank at random. Describe the likelihood that the chosen fish will be a) orange or b) yellow.
Most of the fish are orange. Only a few are either blue or black. So, it is highly likely that an orange fish will be chosen.
None of the fish are yellow. So, it is impossible that one will be chosen.
To find the probability, P, of an event where each outcome is equally likely, use this formula:
P=number of favorable outcomes/number of possible outcomes
This chart describes the fish in the tank.
Solid Color
|
Striped
| |
Orange
|
35
|
5
|
Blue
|
4
|
0
|
Black
|
2
|
4
|
What is the possibility that a fish chosen at random from the tank will be a striped orange fish?
The number of favorable outcomes is the number of striped orange fish: 5.
The number of possible outcomes is the total number of fish in the tank: 35+5+4+2+4=50
Write the number of favorable outcomes over the possible outcomes.
The probability of choosing a striped orange fish is 1/10
