Calculate the standard deviation of the given random variable X. Please, round your answer to two decimal places, if necessary.
X is the number of heads that come up when a coin is tossed three times.

A) $\sigma = 1.4$
B) $\sigma = 0.87$
C) $\sigma = 0.75$
D) $\sigma = 0.25$
E) $\sigma = 0.13$

Question

Calculate the standard deviation of the given random variable X. Please, round your answer to two decimal places, if necessary.  
 X is the number of heads that come up when a coin is tossed three times.
 
A) $\sigma = 1.4$
B) $\sigma = 0.87$
C) $\sigma = 0.75$
D) $\sigma = 0.25$
E) $\sigma = 0.13$

Quizplus · Accepted Answer

The standard deviation of a binomial distribution is given by the formula $\sigma = \sqrt{np(1-p)}$, where n is the number of trials and p is the probability of success. In this case, n = 3 and p = 1/2, so $\sigma = \sqrt{3(1/2)(1/2)} = 0.87$.

Calculate the Standard Deviation of the Given Random Variable X σ=1.4\sigma = 1.4σ=1.4

Calculate the Standard Deviation of the Given Random Variable X $\sigma = 1.4$