Theory question 101
Data PresentationThe number of items produced by a company over a five-year period is given below:
Year: 1978, 1979, 1980, 1981, 1982
Number produced: 4100, 2500, 1500, 1800, 9200
(i) Plot a bar chart for this information
(ii) What is the average production for the five-year period?
Show the model answer
Model answer
(i) Years on the horizontal axis, number produced on the vertical axis with a sensible scale (e.g. 1 cm to 1000); five separate bars of equal width with heights 4100, 2500, 1500, 1800 and 9200; title and labelled axes.
(ii) Total = 4100 + 2500 + 1500 + 1800 + 9200 = 19 100
Average = 19 100 ÷ 5 = 3820 items per year.
Explanation
Bars must have equal widths and gaps; only the heights change.