Mayfield – Data Handling

Lo: • To understand which is the appropriate

graph to test each hypothesis.• To be able to self analyse and adapt my

own work.

4 5 6 7 8 9 10 11 12

MedianLower

QuartileUpper

QuartileLowest Value

Highest Value

BoxWhiskerWhisker

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Boys

Girlscm

Box and Whisker Diagrams.

Anatomy of a Box and Whisker Diagram.

Box Plots

2. The boys are taller on average.

Question: Gemma recorded the heights in cm of girls in the same class and constructed a box plot from the data. The box plots for both boys and girls are shown below. Use the box plots to choose some correct statements comparing heights of boys and girls in the class. Justify your answers.

Drawing a Box Plot.

130 140 150 160 170 180 190

Boys

Girls

cm

1. The girls are taller on average.

3. The girls show less variability in height.

4. The boys show less variability in height.

5. The smallest person is a girl

6. The tallest person is a boy

Sampling Methods

• Random• Stratified

Sampling Methods

• Random• Every person has an equal chance. However

this could lead to an unrepresentative population being represented

• Stratified – Takes a proportional number from each side of the population so that each group is fairly represented

• E.g

• There are the 1183 students at Mayfield High School. The table shows the number of students in each year group for males and females.

Year Group Boys Girls Total

Year 7 151 131 282

Year 8 145 125 270

Year 9 118 143 261

Year 10 106 94 200

Year 11 84 86 170

What should be included in my Report

• Introduction to what you are doing• Your 3 hypothesis including what you predict will actually

happen.• In neat an explanation of what sampling method you will be

using and why for each hypothesis.• A reason for using your specific chart to represent the data.• The scatter graph/ box plot etc for your data• What you found• Can we draw any conclusions on the bigger picture include

any methodological flaws.

Example Hypothesis 1

• Height vs Weight. • I think that when height increases then so

does weight. • I am using a scatter graph to test this.• I will have a line of best fit and it will show

positive correlation.

Example Hypothesis 2

• Comparing the height of boys in year 7 and the height of boys in year 11.

• I think that the boys in year 11 will be taller than the boys in year 7. I also think that the boys in year 7s height will vary more than those in year 11.

• I will use a box plot to test this and a cumulative frequency graph.

What hypothesis can I possibly use with the graphs below

• Pie Chart• Scatter Graph • Cumulative Frequency graph • Box Plots