- 1 Marks
Question
In a QTB examination, where the maximum possible mark in a question is 20 marks
and the Coefficient of Variation is given as 25%, find the variance if the mean score is
A. 3
B. 9
C. 12
D. 15
E. 18
Answer
Answer:
The correct answer is B. 9
Workings:
- The Coefficient of Variation (CV) is defined as: CV = (Standard Deviation / Mean) × 100%
- We are given: CV = 25% Mean = 12 marks
- Let’s substitute these into the CV formula: 25% = (Standard Deviation / 12) × 100%
- Simplify: 0.25 = Standard Deviation / 12
- Solve for Standard Deviation: Standard Deviation = 0.25 × 12 = 3
- Variance is the square of Standard Deviation: Variance = 3² = 9
Therefore, the variance is 9.
- Tags: Coefficient of Variation, Statistical Calculations
- Level: Level 1
- Topic: Statistics
- Series: MAY 2016
- Uploader: Kwame Aikins