Question

A graph consists of two line graphs. It is a convenient way of comparing two data sets of same categories. This graph is a graph.

Answer 1

A double line graph is used to compare two data sets of same categories. It is a combination of two line graphs plotted on same scale.

Following is a double line graph of the number of sit-ups done by a 15 years boy and a 16 years boy in a particular week.

By comparing the data, we can find that the 15-year-old boy increased his count as the week proceeded, whereas the 16-year-old boy was almost consistent on his count.