Problems Involving Mean and Variance of a Probability Distribution

A. Direction: Solve the following problems. 1. The DSWD researcher surveyed the households in a Sitio Libjo, Sto. Nino, Paranaque City. The random variable x represents the number of workers who are qualified in the social amelioration program. The probability distribution of x is shown below. Find the expected value and variance of x. X 1 2 3 P(x) 0.20 0.32 0.28 0.20 2. The random variable x represents the number of vehicles encountered by the student on his way to the school. The probability distribution of x is shown below. X 2 W 5 6 P(x) 0.2 0.05 0.30 0.15 0.30 Find the expected value and variance of X. 3. The following are the results of the study of the number of students failed in statistics and probability in stem class. Use the data and associated probabilities to compute for the expected number of students failed in the subject, and its variance. X 5 6 P(x) 0.08 0.15 0.28 0.27 0.22