1. Time series and line graphs

People are always interested in data that shows changes over time. Data sets that consist of a sequence of observations made over time are called time series and they are often represented with line graphs. Recall that last week, when you were looking at presentation of discrete data, you looked at vertical line charts. We explained that “these cause confusion because of the word ‘line’ in their name. A vertical line chart is a bar chart with skinny bars! Not to be confused with a line graph which is typically used to show a trend over time.” Here, the line on our graph joins successive data points.

Include line graph image such as this showing trend over time