Vocabulary
Statistics - the study of collecting, organizing and interpreting data.
Population - a group of items or individuals from which a sample is taken.
Survey - a question or set of questions used to collect data.
Sample - a randomly selected group, used for collecting data.
Concepts
The probability of an event occurring is found by dividing the number of the desired sample by the total population in the event.
P(a) = Desired OutcomeTotal Population
Rules
- Calculate the total number in the population.
- Find the total number in the desired outcome.
- Divide the desired outcome by the total population.
- Write in the form requested (simplified fraction, decimal or percent).
Example
The table shows how students traveled to school one morning. What is the probability that a student rode their bike to school?
Method |
Students |
Walked |
7 |
On bike |
12 |
By bus |
8 |
By car |
5 |
Solution
Out of a total of 32 students, 12 rode their bikes to school. That is a probability of 1232 = 38.
Pre-requisite Skills
Write Probability as Percentage, Fraction and Decimals (6.9.1)
Error