Chapter 14 · Class 9 ICSE · Formula Sheet

Probability Formulas — Class 9 ICSE

Compute probability of events using sample spaces and apply addition rule.

Key Formulas

Mean

\bar{x} = \dfrac{\sum f_i x_i}{\sum f_i}

Median

\text{Middle value of ordered data}

Mode

\text{Most frequent value}

Probability

P(E) = \dfrac{n(E)}{n(S)}

Worked Examples

1Using: Probability

A die is thrown. Find P(getting an even number).

Step 1: Even outcomes: {2, 4, 6} = 3.

Step 2: Total outcomes = 6.

Step 3: P = 3/6 = 1/2.

Answer: 1/2

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More Class 9 ICSE Formulas

Rational & Irrational NumbersCompound InterestExpansionsFactorizationSimultaneous Linear EquationsIndices (Exponents)

Frequently Asked Questions

How many formulas are in Class 9 ICSE Probability?+
There are 4 formulas in the Probability chapter for Class 9 ICSE. Each formula is essential for solving problems in this topic.
How to remember Probability formulas easily?+
Practice regularly with worked examples, group related formulas together, and use SparkEd's interactive practice mode to reinforce your memory through problem-solving.
Are these Probability formulas enough for exams?+
Yes, these formulas cover the complete ICSE Class 9 syllabus for Probability. Practice applying them to different types of questions for full exam readiness.

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