At first we will know the precise meaning of the term ‘experiment’ and the proper context in which it will be used in our experimental probability.
Definition of experiment: A process which can produce some well-defined results (outcomes) is called an experiment.
Some Experiments and their outcomes:
I. Tossing a coin:
Suppose we toss a coin and let it fall flat on the ground. Its upper face will show either Head (H) or Tail (T).
1. Whatever comes up, is called an outcome.
2. All possible outcomes are Head (H) and Tail (T).
II. Throwing a dice:
A dice is a solid cube having 6 faces, marked as 1, 2, 3, 4, 5, 6 respectively.
Suppose we throw a dice and let it fall flat on the ground. Its upper face will show one of the numbers 1, 2, 3, 4, 5, 6.
The act of
tossing a coin or throwing a dice is called an experiment.
Whatever comes up, is called an outcome.
In an experiment, all possible outcomes are known.
The plural of die is dice.
III. Drawing a card from a well-shuffled deck of 52 cards:
A deck of playing cards has in all 52 cards.
1. It has 13 cards each of four suits, namely spades, clubs, hearts and diamonds.
2. Kings, queens and jacks (or knaves) are known as face cards. Thus, there are 12 face cards in all.
Definition of Experimental Probability: The experimental probability of happening of an event is the ratio of the number of trials in which the event happened to the total number of trials.
The experimental probability of the occurrence of an event E is defined as:Number of trials in which event happened
Solved examples on Experimental Probability:
1. Suppose we toss a coin 100 times and get a head 58 times. Now, we toss a coin at random. What is the probability of getting a head?
Total number of trials = 100.
Number of times head appeared = 58.
2. A coin is tossed 150 times and head is obtained 71 times. Now, if a coin is tossed at random, what is the probability of getting a tail?
Total number of trials = 150.
Number of times head appeared = 71.
Number of times tail appeared = (150 - 71) = 79.