Question

While plotting a line graph, when can we obtain a line parallel to x-axis?

• A. when the variable on the vertical axis is constantly increasing.
• B. when the variable on the vertical axis is constantly decreasing.
• C. when the variable on the vertical axis is constant.
• D. None of the above.

Answer 1

The correct option is C when the variable on the vertical axis is constant.

Consider the following plot of horse ride fare per 30 minutes for different months:

Here, the plot of line graph is horizontal between November-January months because the fair (variable on vertical-axis) remians constant for these months i.e., $\$15$.

Hence, a line parallel to x-axis is obtained when the corresponding variable on the vertical axis remains constant. Option (b) is the correct choice.