KEY WORDS
What is the median?
The middle number in an ordered dataset.
In a stem-and-leaf plot, the stem represents the…
Tens digit (or leading digit).
Which measure is another word for average?
Mean
A graph that is balanced on both sides is called…
Symmetrical
Which team is more consistent: range 5 or range 20?
Range 5
What is the range?
The difference between the highest and lowest value.
Find the median:
12, 14, 16, 18, 20
16
Which measure is affected most by extreme values?
Mean
If the tail is on the left, the distribution is…
Left skewed (negatively skewed)
What does an outlier do to the mean?
Pulls it toward the extreme value.
What is a histogram?
A graph with touching bars.
What is wrong?
1 | 2 8 5 6
Leaves not in order.
Which measure is best for skewed data?
Median
What does a large range tell us about the data?
It is spread out.
Can a dataset be bimodal and skewed?
Yes (if two peaks but uneven tail).
What is unimodal?
A distribution with one clear peak.
How many values are in:
1 | 2 4 6
2 | 1 3
5
Dataset: 5, 6, 6, 7, 7, 30
Which measure best represents this data?
Median
Income data is usually which type of skew?
Right skewed
Create a dataset with a median of 10 and a range of 8.
...
What is right skewed (positively skewed)?
A distribution with a long tail on the right.
Why must leaves be in ascending order?
So the data is organised and easier to read/find median.
Why is the median better in skewed data?
It is not affected by extreme values.
If a graph is symmetrical, which measure is appropriate and why?
Mean (data is balanced, no extreme pull).
Why is it important to look at shape and not just the average?
The average alone can misrepresent the data.