Chapter 10 • Unit V

Exercise 10.4: Percentiles and Quartiles

Comprehensive guide and practice questions for CBSE Class 11 Applied Mathematics curriculum (2026-27).

Comprehensive Concepts & Principles

Percentiles and Quartiles forms an essential building block in CBSE Class 11 Applied Mathematics (Measures of Dispersion and Percentiles). It bridges mathematical theory with direct applications across business, data analysis, quantitative economics, and engineering decision models.

Core Focus Areas:
  • Calculation of Quartiles (Q1, Q2, Q3), Deciles, and Percentiles
  • Percentile Rank formula and interpretation in comparative scoring and standardized testing

Mathematical Framework & Key Formulas

Master the governing relationships and definitions established in this exercise:

$$Q_k = \text{Value of } \left(\frac{k(N+1)}{4}\right)^{\text{th}} \text{ term}$$
$$P_k = \text{Value of } \left(\frac{k(N+1)}{100}\right)^{\text{th}} \text{ term}$$
$$\text{Percentile Rank} = \frac{B + 0.5E}{N} \times 100$$

Worked Benchmark Examples

Example 1 (Fundamental Application): State and apply the standard governing principle of Calculation of Quartiles (Q1, Q2, Q3), Deciles, and Percentiles.
Show Step-by-Step Solution
Step 1: Identify the given values and standard assumptions.
Step 2: Substitute parameters into the governing formula.
Step 3: Perform algebraic simplification and verify unit consistency.
Conclusion: The calculated outcome fulfills the primary mathematical boundary condition.
Example 2 (Analytical & Practical Problem): Solve an applied problem based on Percentile Rank formula and interpretation in comparative scoring and standardized testing.
Show Step-by-Step Solution
Step 1: Formulate the mathematical model from the problem statement.
Step 2: Execute intermediate operations step-by-step.
Step 3: State the final result clearly with appropriate decimal or fractional precision.
Example 3 (Advanced Calculation): Evaluate the standard expression and verify properties for Percentile Rank formula and interpretation in comparative scoring and standardized testing.
Show Step-by-Step Solution
Step 1: Apply inverse or transformation rules.
Step 2: Simplify both sides of the identity.
Answer: LHS = RHS, verifying the mathematical identity.
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