Probability Notes: Class 9 Maths Chapter 15
Class 9 Maths Chapter 15 Probability covers the empirical (experimental) approach to probability, based on the frequency of outcomes actually observed in trials of an experiment.
Overview of Topics & Subtopics (Click to Jump)
1. Empirical Probability
Short Note:
• Experimental (Empirical) Probability of an event E = (Number of trials in which E happened) ÷ (Total number of trials).
• As the number of trials in an experiment increases, the experimental probability tends to get closer to a theoretical value, but at the Class 9 level, probability is studied purely from actual recorded data.
• The probability of an event always lies between 0 and 1, inclusive: 0 ≤ P(E) ≤ 1.
2. Applications
Short Note:
• Empirical probability is calculated from real experiments such as tossing coins, throwing dice, or from survey/statistical data such as results of matches, family sizes, or student marks.
NCERT Textbook Exercise Questions
(ii) P(tail) = 545/1000 = 0.545.