**Learning Intention: **Students will understand the meaning of mean, median, mode and range. They will understand how to calculate an average from given data and be able to work out the range of that data. They will then use the data to explore and compare ratios.

**Success Criteria: **Students will correctly calculate the average and range of the given data and use the data to make some comparisons of ratio.

Statistical values, such as mean, median, mode and range, help us to determine trends in the data. They are used in a variety of ways in business, education and government organisations. For example, a company might want to find out about which customers spend the most money in their shops, so they can target their advertising better. Governments might need to find out about the age groups in their community, so they can distribute funding to health care, aged care, kindergartens, schools, universities, hospitals and other services.

- The
**mean**(or average) of a set of numbers is calculated by adding all the numbers together and dividing by the number of values. It will always be somewhere between the smallest and largest value. What is the average height of students in Year 7 at Hawkesdale P12 College? Is there a height difference between males and females? - The
**mode**is the most frequently represented score. A shoe shop will need to order more pairs of popular sizes – 8, 9 and 10 – than smaller or larger sizes, for example. - The
**median**is the middle value – halfway between the smallest and largest value. - The
**range**is calculated by subtracting the smallest number from the largest number. What is the range of arm lengths in Year 7?