1. The Ogive - A Line Graph of a Cumulative Frequency Distribution
To accompany Hawkes lesson 2.2b(iv)
Original content by D.R.S.

2. Start with a Frequency Distribution
Class Boundaries
Frequency 9 26 23 14 7 11 10 2 1
These are the runners’ times from the 5K race again.
The Ogive uses upper class boundaries (not limits, not midpoints.)
2/22/2019

3. Upper Class Boundaries, + 1 Phony
Note we’ve picked off just the upper class boundaries.
Also add a phony class at the low end with zero frequency. This will “anchor” the ogive to the axis.
Upper C.B.
Frequency 9 26 23 14 7 11 10 2 1
2/22/2019

4. Cumulative Frequencies
Upper C.B.
Freq.
Cumulative Frequency 9 26 35 23 58 14 72 7 79 11 90 10
100 2
102 1
103
Instead of frequencies, the ogive plots cumulative frequencies.
2/22/2019

5. The Ogive
A good chart has a title telling the reader what he is looking at
Descriptive labels
on the axes, too

6. The Ogive Total of 103 runners Anchored at the phony 0
The ogive’s line climbs from frequency 0 up to the total data count.