Statistics
NCERT Exemplar Ch 12
CBSE_NCERT_EXEMPLAR_CH12
Grade 10
Question:
The algebraic sum of the deviations of a frequency distribution from its mean is:
Always positive
Always negative
Zero
A non-zero constant
Step-by-Step Solution
Key Concept: Property of arithmetic mean: $\sum f_i (x_i - \bar{x}) = 0$.
Stepwise Solution:
$\sum f_i (x_i - \bar{x}) = \sum f_i x_i - \bar{x} \sum f_i = \bar{x} N - \bar{x} N = 0$. [1.0 Mark]
Marking Scheme:
• Selecting Zero: 1.0 Mark
Correct Answer: Zero
Confused by the solution? Ask the AI to explain a specific step, tell you where you went wrong, or break down the key trap in this question.