ABSTRACT
This chapter deals with the probability theory. It helps the reader to use the terminology of statistics correctly – experiment, sample space, event, random variable etc, and use the rules of probability correctly. The chapter assists in obtaining the mean and variance of a probability distribution, using the binomial, Poisson and normal distributions, approximating the binomial and Poisson distributions by the normal distribution, and using normal probability paper to estimate the mean and variance of a distribution. The variance of a probability distribution is defined as the expected value of (X - μ)2. As with the mean, this is consistent with the definition of a population variance. The chapter also looks at a practical problem of statistics in engineering.
