Objectives Recognise types of data Construct stem and leaf diagrams Understand grouped frequency distributions Construct cumulative frequency polygons

Types of Data Qualitative Quantitative Height Town of birth Age Eye colour

Types of Data Continuous Discrete Time Cost in £’s Volume Number of children Height Shoe size Weight Number of pets

Stem and Leaf Diagrams 35 35 23 18 25 20 16 22 27 33 41 27 37 17 25 27 29 28 31 32 40 23 1 2 3 4 1 2 3 4 6 7 5 8 9 8 6 7 3 5 2 7 7 7 9 8 5 3 7 1 2 1 1 8 means 18

Stem and Leaf Diagrams 5.2 6.6 4.3 8.3 5.1 7.5 8.6 7.1 7.8 2.2 6.6 5.8 3.5 7.5 6.1 3.8 2.5 2.7 8.8 4.8

Grouped frequency A sample of the red cell count per 1mg of blood from visits made to the doctor by 150 patients, assume data is continuous

Class 5 - 9 7 4.5 5 9 9.5 midpoint lower class boundary 5 9 lower class limit upper class limit 9.5 upper class boundary class width

25 50 75 100 125 150 175 4.5 9.5 14.5 19.5 24.5 29.5 34.5