I'll elaborate a little bit,
There is an outbreak of swine flu, and the number of cases increases weekly as shown in the following table
WeeksNumber of cases of swine flu03216029632004320557061050
Plot the data from this table using Excel and hence predict how many cases there will be at the end of week 9. By trial and error, predict how long it will be before there are 8 million cases of flu.
All I can say is "do what you are told". Use Excel to plot the graph. Look at the height of the graph at t= 9 to see what "how many cases there will be at the end of week 9". Look at the graph, increasing the range if necessary, to see what t is when the graph has height 8000000.