Probability Question 134
Question: In a binomial distribution the probability of getting a success is 1/4 and standard deviation is 3, then its mean is
[EAMCET 2002]
Options:
A) 6
B) 8
C) 12
D) 10
Show Answer
Answer:
Correct Answer: C
Solution:
Probability of success $ p=\frac{1}{4} $
Probability of unsuccess $ q=\frac{3}{4} $
Mean = np
Standard deviation = $ \sqrt{\text{Variance }} $
$ \Rightarrow $ Variance = 9
Therefore $ npq=9 $
Therefore $ n.\frac{1}{4}.\frac{3}{4}=9 $
Therefore $ n=48 $ Mean $ =np $
$ =\frac{1}{4}\times 48=12 $ .
BETA
