- CFA Exams
- CFA Level I Exam
- Topic 1. Quantitative Methods
- Learning Module 4. Common Probability Distributions
- Subject 5. Binomial Distribution
CFA Practice Question
For random variable x from a binomial distribution with N = 20 and p = 0.3, the standard deviation is ______ (to nearest 0.01).
B. 4.20
C. 2.05
A. 0.30
B. 4.20
C. 2.05
Correct Answer: C
The standard deviation is sqrt[Np(1 - p)]. Here, N = 20 and p = 0.3. So, the standard deviation is sqrt[(20)(0.3)(1 - 0.3)] = 2.05 (to the nearest 0.01).
User Contributed Comments 3
| User | Comment |
|---|---|
| TammTamm | WOW! I was actually able to work this one out without guessing. Yippee!!!!! |
| magicchip | @TammTamm: you are on the right track! :-) |
| DonAnd | way to go TammTamm! |