Solve for the mean and standard deviation of the following b

Solve for the mean and standard deviation of the following binomial distributions. a. n = 30 and p = 0.50 b. n = 70 and p = 0.45 c. n = 110 and p = 0.50

Solution

a)
Mean ( np ) =30 * 0.5 = 15
Standard Deviation ( npq )= 30*0.5*0.5 = 2.7386
b)
Mean ( np ) =70 * 0.45 = 31.5
Standard Deviation ( npq )= 70*0.45*0.55 = 4.1623
c)
Mean ( np ) =110 * 0.5 = 55
Standard Deviation ( npq )= 110*0.5*0.5 = 5.244