Probability is a branch of mathematics that is widely
used in genetics, insurance, finance, medicine, sociological surveys,
marketing and science. We use probability to measure the chance or likelihood of an event (or events) occurring in the future.
An event is something that may or may not occur at some time or
during some period in the future.
When we talk about events in terms of chances, we could make statements
"I will probably play tennis this summer"
"It isn't likely that I will be invited to play in the
Australian Open Tennis Tournament"
"My chances of winning Tattslotto are not very good"
We could describe the expected occurrence of an event (or events) with
the words probably, likely or chances. These words tell us something
about whether or not the event is expected to occur; but the statements
are very vague. We study and apply probability to enable us to
better quantify or measure the chance of an event (or events) occurring in
A probability experiment is a test in which we perform a number of trials to enable us to measure the chance of an event occurring in
the future. The results from a probability experiment may reveal a
known truth or lead us to discover something about the probability (or
chance) of an event occurring in the future.
A trial is a process by which an outcome is noted.
Throwing a die, tossing a coin, rotating a spinner and drawing a card
from a pack of playing cards are all examples of probability experiments.