# S5-4: Calculate probabilities, using fractions, percentages, and ratios.

Elaboration on this Achievement Objective

This means that students will calculate probabilities for probability situations that involve two or more events. These events may be independent (for example rolling two dice, or tossing two coins) or dependent (for example drawing two cards from a deck of cards without replacement, or choosing to students from the class at random). They will be able to model these situations using models such as tree diagrams, tables and systematic lists and assign theoretical probabilities as proportions using fractions, percentages and ratios, for example the odds of winning the game are 2:3.

Students should also be able to estimate probabilities given results of sufficient trials. Such estimates are always approximate, and require use of equivalent proportions, for example an experiment results in a ratio of 43 blue: 79 red. An estimate of the probability of red is 2/3 or 67%.