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

Start with a Frequency Distribution Class Boundaries Frequency 19.99995-24.99995 9 24.99995-29.99995 26 29.99995-34.99995 23 34.99995-39.99995 14 39.99995-44.99995 7 44.99995-49.99995 11 49.99995-54.99995 10 54.99995-59.99995 59.99995-64.99995 2 64.99995-69.99995 1 These are the runners’ times from the 5K race again. The Ogive uses upper class boundaries (not limits, not midpoints.) 2/22/2019

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 19.99995 24.99995 9 29.99995 26 34.99995 23 39.99995 14 44.99995 7 49.99995 11 54.99995 10 59.99995 64.99995 2 69.99995 1 2/22/2019

Cumulative Frequencies Upper C.B. Freq. Cumulative Frequency 19.99995 24.99995 9 29.99995 26 35 34.99995 23 58 39.99995 14 72 44.99995 7 79 49.99995 11 90 54.99995 10 100 59.99995 64.99995 2 102 69.99995 1 103 Instead of frequencies, the ogive plots cumulative frequencies. 2/22/2019

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

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.