Q. How to plot Line Graphs?

Ans.

Line graphs can be useful in analyzing data. They are particularly helpful when you are interpolating or extrapolating information from your data set.

Example: A start-up Internet company tracks the number of "hits" their website receives at different times in the day. Make a line graph of the information. Estimate the number of hits the website receives at 4:30pm, 9:30pm and 12:00am.

Solution: To draw a line graph of the above information, first decide on the axes. Let the x-axis be the time of day and the y-axis be the number of hits. Then draw dots at the proper places on your graph.

Estimating the number of hits the website received at 4:30pm and 8:30pm can be done using the line graph. Draw vertical lines at 4:30pm and 8:30pm and the points of intersection with the line graph represent the estimated number of hits at these times. You can estimate the number of hits at 12:00am by extending the graph another two hours. Use the previous few hours as a way to predict the future hits. All three of these estimates are shown with orange lines in the graph below.

The estimated numbers of hits are 300 at 4:30pm, 260 at 9:30pm and about 110 at 12:00am.