Probability

Probability

1. Random Experiment

   • Random Experiment may result in two or more outcome. For eg: (i)Tossing a coin (ii)Throwing a dice

2. Sample Space

   • Set of all possible outcomes of an experiment

3. Event

   • An outcome of a random experiment

4. Equally likely events

   • The different outcomes have the same as equal chance of occurence

5. Probability of an event can never be less than 0 and greater than 1.

6. Probability of Events

   • Sum
     • Sum of probability of all events is always one. For eg:P(E1)+P(E2)+P(E3)+...+P(En)=1
   • Complimentary Event
     • P(E)+P(E')=1 P(E')=P(not E')= complimentary events
   • Certain Events
     • Probability of an event is equal to 1.
   • Impossible Event
     • Probability of an event is equal to 0.

7. Types

   • Classical probability
     • Probability of an event denotes likelihood of its happening. P(E)=(No of event favourable)/(Total no of events possible)
   • Measurement Probability
     • When repititon of an experiment can be avoided for exact probability. Probability=(No of favourable outcomes)/(No of all possible outcome)
   • Empirical Probability
     • When probability is based on an actual experiment suppose event E is happened when experiment is performed. P(E)=(No of times event E occured)/(No of times Experiment E is performed)