Year 9 Science · Unit 4 · Lesson 12
Challenge Worksheet
Learning Goals
Odd one out
Circle the item that does not belong in each group. Then explain why it doesn't fit in the answer column.
| # | Group | Your answer (odd one + reason) |
|---|---|---|
| 1 | Mean Median Mode Range | |
| 2 | Summarise the data Describe the centre Predict the future Show the spread | |
| 3 | Sum divided by count Middle of ordered data Most frequent value Highest minus lowest | |
| 4 | Median income Median house price Mean with a billionaire included Resistant to outliers |
Evaluate the data
A student reports...
"I measured how many minutes 5 classmates spent on homework one night: 12, 15, 15, 18 and 90 minutes. The average (mean) is 30 minutes, so I will tell the class that a typical student does 30 minutes of homework."
(a) Verify the student's mean by showing the full calculation, then calculate the median of the same data.
(b) Explain why the mean of 30 minutes is misleading here. Identify the outlier and describe its effect, then state which average better describes a typical student and why.
(c) The Australian Bureau of Statistics reports the median, not the mean, for incomes and house prices. Using what you found above, explain in full why the median is the better choice for describing a typical Australian, and outline two further benefits of using descriptive statistics to report on a whole population.
Wrap Up
In one sentence, what was the main idea of this lesson?