PROBABILITY
In the real world, some events happen by chance. In mathematics, we study those possibilities through probability. We’ll look at simple probability and ways to express probability.
In the study of probability, there is theoretical probability where mathematically this is the way the events should occur. However, in actuality they may not occur exactly as expected. We will test actual outcomes against theoretical outcomes.
Simple Probability Cindy has done well on her last test and gets to select a star from the jar. What are her chances of selecting a gold star?
There are 11 stars total in the jar with four of them being gold. Thus, her chance of selecting a gold star is 4 chances out of 11. |
Writing Probabilities as Ratios
The probability of selecting a gold star out of the entire container of stars is 4 out of 11. Probability can be written as a ratio. Number of possible outcomes : all possible outcomes or
What is the probability of selecting a black star? Since there are no black stars then that would be 0 : 11 or 0/11 or no chance of happening.
What is the probability of selecting any color of star in the jar?
Since this covers all the stars then the probability would be 11 : 11 or 11/11 or 1, a sure thing that it would happen. |
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 Click on the icon to find and practice topics for this unit. |
| Click here to watch and practice simple probability. |
| Unit 34 Probability Using a Spinner Worksheet |
| Unit 34 Probability With a Single Die Worksheet |
| Click here to watch basic probability. |
| Unit 34 Calculate Activity |
