Time series graphs show data over a time period. The time period is always shown on the x-axis. Data points are joined chronologically by line segments.

A scatter graph is a visual representation for bivariate data. It can be useful when determining the nature of the relationship between the variables.

Problem solving with scatter graphs and time series

Maths

Checking understanding of scatter graphs

Checking understanding of correlation

Estimating from scatter graphs

Interpolation versus extrapolation

Outliers in scatter graphs

Constructing time series graphs

Interpreting time series graphs

In the prior unit, pupils explored different graphs and charts as a way of presenting data visually. Pupils were introduced to scatter graphs and learnt how to construct them. In this unit, this understanding is extended to using a line of best fit to allow interpolation.

In this unit pupils will learn how to interpret and extract data from scatter graphs and time series graphs.

Graphical representations of data: scatter graphs and time series

Yes, the point does not fit the rest of the data.

It depends, outliers should be investigated further.

Lucas plots this scatter graph. He says, “Point P must be an error.” Is Lucas definitely correct?

Aisha: Both variables might be affected by a third variable.

Jacob: one variable is definitely causing the other to increase.

Lucas: The variables might be completely unrelated and correlate by chance.

Laura: One variable might be causing the other to increase.

This scatter graph shows positive correlation. Which of these Oak pupils are correct?

{{ }} is when you estimate values that are outside the range of available data.

Yes, you can continue the trend for another 10 years.

Yes, there is a clear upward trend which is likely to continue.

No, you cannot use data for England to predict for Wales.

No, there is unlikely to be 90 million people in Wales in 2050

The time series graph shows data about the number of daily internet users in England. Sam says, “I can use the graph to predict there will be 90 million internet users in Wales in 2050.” Is Sam right?

A scatter graph is a visual representation for {{ }} data.

Andeep: Wow! That cannot just be coincidence.

Jun: The two variables have a negative correlation so the headline is true.

Lucas: Hannah's a popular name at the moment, it is unrelated to landlines.

Sam: There must be a third factor at play to link these.

A reporter writes the following headline for the Oak Daily News. Which of these Oak pupils are correct?

{{ }} is when you estimate values that are within the range of available data.

This time series graph shows the temperatures in Sheffield between 2012 and 2019. In how many quarters does the mean maximum temperature reach between 10°C  and 20°C? {{ }} quarters.

This scatter graph shows {{}} correlation.

The time series below shows data from the ONS about the average annual income per person each year. What is the approximate median income in the year 2014?

The time series below shows data from the ONS about the average annual income per person each year. What is the approximate smallest difference between the mean and median incomes?

The time series graph shows data on average houses prices over a number of years in the UK. The graph shows {{ }} years where average house prices were below £200 000

Problem solving with scatter graphs and time series

Lesson outcome