Tables and charts for OCR GCSE Maths
This page covers the following topics:
1. Frequency tables
2. Frequency diagrams
3. Bar charts
4. Pie charts
5. Vertical line charts
Frequency tables represent large amounts of data in a more efficient way. The mean of grouped data = (frequency × class midpoint) / total frequency.
In a frequency diagram, frequencies are plotted against the midpoints of each group and connected by straight lines. Cumulative frequency diagrams plot a running total frequency against the upper bounds of classes.
Bar charts represent the frequency of grouped data by the height of bars, with gaps between the groups. Use a key when comparing 2 sets of data on the same bar chart.
Pie charts are useful to visually represent and compare the sizes of sets of data; calculate the angles of each segment using the equation below. A protractor and compass are needed to draw pie charts.
Vertical line charts represent ungrouped, discrete data with vertical lines that don’t touch each other.
This pie chart shows 50 customer’s favourite type of pie from a cafe. How many more people prefer blueberry pie over cherry pie?
People who prefer blueberry pie: (93.6/360) × 50 =13.
People who prefer cherry pie: (57.6/360) × 50 = 8.
13 - 8 = 5 more people prefer blueberry pie than cherry pie.
The number of classes a group of college students have in a week is shown in the bar chart below. Find the percentage of students who have more than 15 classes in a week.
The bar chart below shows how many fruits a group of adults and children eat in a week. Which fruit is eaten most by adults and children combined?
20 people were asked how many hours they exercise in a week:
hours of exercise, frequency;
0 - 2, 4;
3 - 5, 9;
6 - 8, 5;
9 - 11, 2.
Construct a bar chart with the data in this table.
The heights, h, in centimetres, of every tree in a park are: 334, 140, 386, 210, 236, 322, 213, 119, 151, 279, 395, 186, 128, 316, 102, 245, 375, 288, 302. Construct a grouped frequency table from this data.
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