ABSTRACT
This chapter presents three important facts about sample means drawn at random from normally distributed populations. It presents a theorem which has more general application, since it is not restricted to the normal distribution. The chapter presents the basic material related to hypothesis testing, assuming large samples drawn at random from a population. It introduces the standard normal distribution. The chapter describes a new distribution known as the Student's t distribution which permits exact inferences to be made, when sample statistic is computed from a sample of any size. A hypothesis is a statement of belief, which may or may not be true about a population parameter. The test of a hypothesis is a comparison of the statement of belief with newly and objectively collected facts. If the newly collected facts are shown to be consistent with the stated belief, the hypothesis is accepted.
