Lesson 1
1. Lesson 1
1.7. Explore 3
Module 1: Probability
In Try This 2 you found that probabilities can be expressed as fractions, decimals, percentages, and in words. Now try Self-Check 1 to test your abilities in demonstrating these skills.
Self-Check 1
Answer “Build Your Skills” question 1 on page 154. Answer
From your work in Try This 2 and Self-Check 1, you may have noticed a pattern in the way probability is calculated as a fraction. The pattern can be condensed into a formula. The experimental probability of an event occurring can be calculated from a frequency table using the following formula.
Source: MathWorks 12 Student Book/Teacher Guide. (Vancouver:Pacific Educational Press, 2011.)
Outcome |
Frequency |
1 |
5 |
2 |
9 |
3 |
6 |
4 |
11 |
5 |
4 |
6 |
1 |
Total |
36 |
From the frequency table, the chance of rolling a 5 is 
That is because a 5 occurs 4 times out of 36 rolls.
Similarly, the chance of rolling a 2 is 
That is because a 2 occurs 9 times out of 36 rolls.