Question

Suppose a binomial event has a probability of success of 0.3, and 750 trials are performed. What is the standard deviation of the possible outcomes? Round your answer to two decimal places.

A. 16.20
B. 12.55
C. 8.22
D. 10.61

Answer 1

Answer: B. 12.55

Step-by-step explanation:

Given: In a binomial event , the probability of success = 0.3

i.e. p =0.3

Then, q=1-P=1-03=0.7

The total number of trial performed n= 750

Now, the standard deviation of the proportion is given by :-

$\sigma=\sqrt{npq}\\\\\Rightarrow\sigma=\sqrt{750\times0.3\times0.7}\\\\\Rightarrow\sigma=\sqrt{157.5}\\\\\Rightarrow\sigma=12.5499003\approx12.55$

Hence, the standard deviation of the possible outcomes = 12.55