Hello!!
I have seen TWO different ways of figuring out the median in the small groups for a three median line. One person has told me to find the middle between the two middle (?) points, another has said to get all the points down on paper and organise them from largest, to smallest point.
What is the best way to get the median points in the group? Thank you!
Please help as I am very confused about three median lines (if there is a question on them I'll probs leave it till last so I have more time on it)
Usually in exam questions you're given a scatter plot or a time series with points already plotted on. So for example
In the above example, to find the 3 median line, first you want to split the points into 3 equal groups, so that each group has the same amount of data points. This graph has 15 data points, so you can equally divide them into 3 groups of 5 each. So the three groups become:
Note that if this graph had a number of points not divisible by 3, say 14 points, you would split the groups such that the first and the 3rd group have an equal amount of points. So the groups would have 5, 4 and 5 points respectively.
So first you find the median vertically for each group so along the y axis.
Then you need to find the median horizontally for each group, so along the x axis.
Now, we notice that in the second group, the median points vertically and horizontally are different. So to find the median for that group, we draw an imaginary vertical and horizontal line going through each point, and the point at which they intersect (the blue dot) will be the median point for that group.
Then at the end you draw in the 3 median line. Hope this helps!
Home
Help
Search
Login
