Key Concepts:
- Using Proportions to Determine Probabilities: Sometimes, instead of raw counts, probability is given as a ratio or percentage.
- Finding Missing Values Using Probability Equations: Probability information can be used to determine unknown group sizes.
Skills Covered:
- Solving probability problems where only proportions or percentages are given.
- Setting up and solving algebraic equations involving probability.
Example Problems:
- A conference has 200 attendees. If the probability of selecting someone from Group A is 0.35 and from Group B is 0.50, how many people are in Group C?
- A school has 800 students. If 60% of students are in Grade 9 or 10, how many are in Grade 11?