1. Inferences to the population
You will need analyse a sample from a population for your investigation. After you have referred to the box and whisker plots in your sample eg spread etc you then will need to refer back to the population.
If there is no overlap (see to the side) between the two boxes you can conclude that “there is a significant difference between the ….. back in the population”. If If there is an overlap between the two boxes you can conclude that “there is no significant difference between the ….. back in the population”.

2. Inferences to the populationUQ
If there is the median of one box is greater than the UQ of the other (see to the side) you can conclude that “there is likely to be a difference between the ….. back in the population”.
If not you can conclude that “there is not likely to be a difference between the ….. back in the population”.
median

3. Inferences to the populationUQ
I notice there is an overlap so there is no significant difference between the heights of Year 9 boys and girls back in the population
I notice that the median of one box is not greater than the UQ of the other so there there is not likely to be a difference between heights of Year 9 boys and girls back in the population.
I notice that the Year 9 Girl’s heights are more spread out than the boys. (Range of girls = … whereas boys’ range = …)
Worksheet
median
Year 9
Boys
Year 9
Girls