GCSE Secondary Maths Age 13-17 - Probability & Statistics: Time/Series Graph - Explained

The video tutorial explains how to interpret a time series graph showing the percentage of villagers using a shop from 1980 to 2010. It describes the trend of decreasing usage over time and demonstrates how to predict future usage for 2020 using a line of best fit. The tutorial also discusses the reliability of such predictions, noting that predictions beyond the given data range are uncertain. Finally, it covers the allocation of marks for related exam questions and the usefulness of drawing trend lines.

What does the time series graph represent in the context of the village shop?

• The percentage of people using the village shop

• The total population of the village

• The number of shops in the village

• The annual revenue of the village shop

What is the purpose of drawing a line of best fit on the graph?

• To show the trend of the data

• To highlight the highest percentage

• To mark the year 2020

• To connect all data points

What percentage of people is predicted to use the village shop in 2020?

• 15%

• 25%

• 20%

• 10%

Why is the prediction for the year 2020 considered unreliable?

• The prediction is based on a different village

• The prediction is outside the given data range

• The shop was closed in 2020

• The graph does not include data for 2020

What range of percentages was accepted for full marks in the prediction question?

• 10% to 14%

• 13% to 17%

• 15% to 19%

• 18% to 22%