1. Quick Question
Determine the best “average” to use for the following examples:
Average age of year 11 students
Average shirt size for stocking a retail store
Average result from a maths exam
Average house price in a street.
Average age of year 11 students: Mode – keeping to whole years, ie “How old will you be this year?”
Average result from a maths exam: Mean
Average house price in a street: Median – as outliers can affect the mean and it is unlikely to be a mode.

2. Find the mean and median of these sets of data
2, 8, 9, 9, 10, 11, 11
8, 8, 9, 9, 10, 10, 11
8, 9, 9, 9, 10, 11, 23
Which measure is the best at representing the set?

3. Mean, Median or Mode?
The mean is typically used as an average, but one or two outliers (extreme scores) can greatly increase or decrease its value.
When the mean is affected by outliers, the median is a better measure of central tendency.
The mode is often used with discrete data.

4. Example:
Tim looks at some apprentice weekly wages in different sectors.
$360 $450 $380 $360 $390
$1200 $420 $410 $405 $370
Find the mean, median and mode and determine which value gives the best measure of a typical apprentice wage. Why?

5. All Questions
Ex 10D
starting page 325