3.5.3 - Time Series Plot

time series plot displays time on the \(x\)-axis and a quantitative response variable on the \(y\)-axis. Minitab Express will construct time series plots (Graphs > Time Series Plots) and will conduct time series analyses which are covered in upper-level statistics courses. Here, you should be able to interpret a time series plot.

Example: Deaths by Horsekicks Section

Source: https://commons.wikimedia.org/wiki/File:R-horsekick_totals-by_year.svg

The time series plot above of "Deaths by horsekick in Prussian cavalry corps, 1875-94" displays the number of annual deaths in each of these 20 years. In other words, one quantitative variable is examined over time.

Example: Changes in Religious Affiliations Section

Source: Duncan Keith: https://commons.wikimedia.org/wiki/File:Bsa-religion-question-1983-2006.svg

The time series plot above presents data from the British Social Attitudes Survey concerning religious affiliation. Here, percentages are compared for three different groups over time. We can see that the proportion of individuals who identify as Christian decreased during this time while the proportion who have no religion is increasing and the proportion of other non-Christians has stayed relatively steady and low.