A random variable represents the number of successes in 30 Bernoulli trials, each with probability of success p =0.5.

A) Find the mean and standard deviation of the random variable.

B) Find the probability that the number of successes lies within 1 standard deviation of the mean.

**Solution:-**

A) The mean of the random variable is 15.

The standard deviation of the random variable is approximately 2.739.

B) P(# of success lies within 1 standard deviation of the mean) = .638