Term 2 Week 6

After a whistle stop tour of percentages we are now moving to probablility. This is a very hands on subject where we can explore how chance works, and have fun tossing coins and rolling dice.

We have all heard expressions like 'you have a 50-50 chance' but what does this mean?

It simply means that the likelyhood of something working out is 1 chance out of 2 - ie a 50% or 1/2 chance.

Much study has been done on understanding chance and probability - particularly when there is money to be made (or lost!)

To formalise the maths of chance we write the chance that something will happen as a ratio of what we want to happen over number of possible ways things could happen.

So the probablility of winning the toss in a football match is 1 chance of heads over 2 (heads or tails) or again a 50% or 1/2 chance.

We call the range of possible out comes the 'sample space' and put curly braces around it to make it look flash:

What is the sample space for a 6 sided dice? {1, 2, 3, 4, 5, 6}

So we can work out the probablility of getting a '2':

P('2') = 1 / 6
(ie 1 desired outcome ('2') out of a sampe space with 6 things in it: {1,2,3,4,5,6})

By calculating and comparing probabilities for things it is possible to make more informed choices about taking risks.

It is said that mathemeticians never gamble - because they can calculate the exact probability that they are going to lose their money!

Probability Assignment 1 is here

.
.