Find the Best Horizontal Axis Scale for Time Data in a Scatter Plot

Question

A scatter graph is being plotted for this data. 
Time (seconds): 71, 135, 14, 116, 58 
Height (m): 29, 37, 6, 31, 18 
Time will be plotted on the horizontal axis below. What numbers should replace A and B to give the best scale for plotting the data? (A blank horizontal axis with 0 on the left, A as the first marked tick after 0, and B as the final marked tick on the right is provided)

Accepted Answer

A = 20, B = 140

Answer

Step 1: Identify the range of the time data. The minimum time value is 14 seconds, and the maximum time value is 135 seconds. Step 2: Choose a scale that is easy to plot and covers the full range of data, with small buffer space beyond the min and max for clarity. A round number interval (like 20) works well for readability. Step 3: Determine the first marked tick (A) after 0. Since the smallest data point is 14, a tick at 20 is a logical first interval that is close to the minimum value and follows a consistent scale. Step 4: Determine the final marked tick (B). The largest data point is 135, so a final tick at 140 provides a small buffer above the maximum value and aligns with the 20-interval scale (0, 20, 40, ..., 140) that fully contains all time data.