Estimating Standard Deviation from Mean Deviation
If value of mean deviation is 16, then the value of standard deviation is-
- 4
- 8
- 20 — Correct Answer
- 64
Explanation:
Correct Answer: 20
There is a fixed empirical relationship between Standard Deviation (S.D.) and Mean Deviation (M.D.) in a normal distribution: S.D. = 5/4 × M.D.
Step-by-Step Calculation
- Given: Mean Deviation (M.D.) = 16
- Formula: S.D. = 5/4 × M.D.
- S.D. = 5/4 × 16 = 5 × 4 = 20
Key Statistical Relationships
| Relationship | Formula |
|---|---|
| S.D. from M.D. | S.D. = (5/4) × M.D. |
| M.D. from S.D. | M.D. = (4/5) × S.D. |
| Variance from S.D. | Variance = S.D.² |
| Standard Error | SE = S.D. / √N |
| Coefficient of Variance | CV = (S.D. / A.M.) × 100 |
Important Note
- S.D. is always greater than Mean Deviation (S.D. > M.D.)
- S.D. is the ideal measure of dispersion
Why Other Options Are Wrong
- 4 → that would be M.D. / 4, no standard formula gives this
- 8 → half of M.D.; no valid formula
- 64 → that would be M.D. × 4; incorrect application
📚 About this Topic — Animal Genetics & Breeding
This multiple choice question is from Animal Genetics & Breeding, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Genetics & Breeding to strengthen your preparation.
