Key Words
What measure of centre is the middle value of an ordered dataset?
Median
Which graph is best for showing categories of data?
Bar graph
Find the median:
4, 6, 8, 10, 12
8
A graph that is balanced on both sides is called:
Symmetrical
Dataset:
4, 5, 6, 6, 7, 20
What number is the outlier?
20
What is the difference between the largest and smallest value in a dataset?
Range
Which graph has touching bars and shows numerical intervals?
Histogram
Find the range:
5, 9, 12, 15
10
If the tail of the graph goes to the right, the distribution is:
Positively skewed
Dataset:
2, 3, 3, 4, 5
What is the mode?
3
What do we call a value that is much larger or smaller than the rest of the data?
Outlier
Which graph shows parts of a whole?
Pie chart
Find the mean:
2, 4, 6
4
If the tail goes to the left, the distribution is:
Negatively skewed
Dataset:
4, 5, 5, 6, 7, 25
Is the distribution positively or negatively skewed?
Positively skewed
Which measure of centre is found by adding all values and dividing by the number of values?
Mean
Which graph would be best to show how many goals each NRL team scored this season?
Bar graph
Find the mode:
3, 5, 5, 7, 9
5
In a skewed distribution, which measure of centre is usually better?
Median
Why is the median better than the mean when data is skewed?
Because the median is not affected as much by extreme values.
A dataset has two values that appear most often. What is this called?
Bimodal
Which graph is best for showing the distribution of numerical data?
Histogram
Which measure of centre is most affected by outliers?
Mean
If one extremely large value is added to a dataset, what will happen to the mean?
It increases / is pulled toward the outlier
Dataset A:
5, 6, 6, 7, 7, 8
Dataset B:
5, 6, 6, 7, 7, 30
Which dataset is skewed and why?
Dataset B because the value 30 is an outlier that pulls the distribution to the right.