Descriptive statistics are used to describe or summarize data in ways that are meaningful and useful.

Lesson 1 of 7: Learning Outcomes

At the end of this lesson, you should be able to

1. organise a set of data by using tables and diagrams such as frequency table and histogram.
2. describe the central tendency of a set of numerical data by using the mean, median and mode.
3. describe the spread of a set of numerical data by using interquartile range and standard deviation.

Lesson 2 of 7: Organise & Visualise Data (5 mins)

We need to organise raw data so that we can draw some basic conclusions on the findings.

For example, the raw data below does not reveal much about the different blood types. But, once we organise data in the forms of table & charts, we can draw some basic information from them

Click on cards below to know what is raw data, frequency table or bar chart.

• Raw Data
• Frequency Table
• Bar Chart

Data Visualisation

We can sort data into two types : ungrouped or grouped. Ungrouped data is one given as individual data points, while grouped data is one given in intervals.

For large data sets, it is necessary to group them into intervals. We can use Frequency Distribution Table, Histogram and Stem and Leaf Plots to visualise the data sets.

• Frequency Distribution Table
• Stem and Leaf Plots

Knowledge Check