DESCRIPTIVE STATISTICS: PICTORIAL (11 in book) pg 95 Flashcards
What are Histograms?
Histograms are similar to bar charts but are used to display continuous data. It is common to present the vertical axis as frequencies
or as percentages.
(think bell curve shape graph for example)
Pie chart info
Pie charts can only be used with one data set but they have a real impact when illustrating percentages and proportions both in
relation to each other and the whole. The circle represents 100% of the data and segments represent a proportion of a particular
category within the data set. Using more than five segments can be distracting and no single segment should ordinarily be less than
2% of the whole. To give more impact segments can be exploded and in 3D as in the example below. Segments can be labelled or a
key can be used.
Table info
Tables are good for determining the extent of a problem and for summarising data that has been subjected to analysis. They can be
used with most types of data (not just numerical) and can vary immensely depending on the level of complexity and the data displayed. Complex detailed tables benefit from divisions using horizontal and vertical lines to help the reader. If a table becomes too complex consider using more than one table or using a summary of some of the data.
Bar chart info
Bar charts are a good way of presenting discrete data such as frequency – bars are of equal width with the height representing the
frequency. Usually there are gaps between bars or sets of bars. They can provide good visual impact for a problem so long as the
chart is not overcrowded by the use of too many bars.
Frequency polygon info
A frequency polygon is a pictorial representation of a frequency table, where dots representing the frequency (vertical axis) and interval (horizontal axis) points are joined. This method is often used instead of a histogram when it is desirable to compare two or more sets of data. The example below could be workloads for two departments over a specific time period.
