Probability

Introduction

You have studied about experimental (or empirical) probabilities of events which were based on the results of actual experiments. We discussed an experiment of tossing a coin 1000 times in which the frequencies of the outcomes were as follows:

Head : 455 Tail : 545

Based on this experiment, the empirical probability of a head is 455/1000 , i.e., 0.455 and that of getting a tail is 0.545.

We know, in advance, that the coin can only land in one of two possible ways — either heads up or tails up (we dismiss the possibility of its ‘landing’ on its edge, which may be possible, for example, if it falls on sand). We can reasonably assume that each outcome, heads or tails, is as likely to occur as the other. We refer to this by saying that the outcomes head and tail, are equally likely.