Time series graphs

A line graph shows the midday temperature in a town on the first day of each month. The table gives the plotted values.

1. Write down the month in which the temperature was 13°C.
2. Work out the difference between the temperature in June and the temperature in January.

The time series graph shows the number of ice creams a kiosk sold each month from January to June.

1. Write down the number of ice creams sold in April.
2. Between which two consecutive months was the biggest increase in sales?

A shop sells woolly hats. The table shows the number of hats sold in each quarter of 2024 and 2025.

1. Describe the pattern in sales within each year.
2. Describe the trend in sales from 2024 to 2025.

A shop records its ice cream sales (number of tubs) each quarter for three years.

1. In which quarter are sales highest each year? Give a reason for this.
2. Describe the overall trend in sales.
3. Estimate the sales in Quarter 3 of Year 4.

A gym records the number of new members who join each week. The time series graph shows the numbers for the first 8 weeks.

1. Draw a trend line on the graph, by eye.
2. Use your trend line to estimate the number of new members in Week 10.
3. Give a reason why an estimate for Week 52 would not be reliable.

The table shows the number of visitors to a website each day for one week.

Draw a time series graph for this information.

The number of visitors to a museum (hundreds) on six days is shown.

1. Work out the 3-point moving averages.
2. What do the moving averages show about the trend in visitors?

A company's sales rose from £192000 in January to £198000 in June.

The company prints a line graph of its monthly sales. The vertical axis of the graph starts at £190000 and ends at £200000. The headline above the graph says "Sales have rocketed!"

Explain why the graph could be misleading.

A company's yearly profit is plotted against the year number (Year 1 is 2019). A trend line is drawn that passes through the points (1, 20) and (5, 36), where profit is in £ thousands.

1. Work out the gradient of the trend line and say what it represents.
2. Use the trend line to predict the profit in Year 8.
3. Give one reason why this prediction may not be reliable.

An estate agent draws a time series graph to show how average house prices in a town have changed.

Write down two reasons why the graph is misleading.

A bookshop recorded the number of books it sold each month from January to June.

The shop's target was a mean of 250 books sold per month.

Did the shop meet its target? You must show your working.

The table shows the amount of electricity, in kilowatt hours, a household used in each quarter of two years.

The first six points have been plotted on the time series graph.

1. Complete the time series graph by plotting the last two points and joining them.
2. Describe the trend in electricity use over the two years.

A factory records the number of bicycles it makes each month.

1. The factory manager says, "The mean monthly output for these six months is more than 400." Show that the manager is correct.
2. Work out how much greater the mean output for April to June is than the mean output for January to March.

The table shows the number of members of a gym at the end of each year.

1. Show that the number of members increased by the same percentage each year.
2. Assuming this trend continues, predict the number of members at the end of 2024.
3. Give one reason why your prediction may not be reliable.