A suitable scale for the number line below the box-and-whisker plot is one that increments by 5.
To determine the most appropriate scale for the number line, we consider the range of the data set.
The smallest value in the data set = 14
The largest value in the data set = 46
Arranged data set: 14, 18, 21, 27, 32, 38, 46
The range for the data set = 32 (46 - 14)
The most suitable scale for the number line should include all values from 14 to 46.
A scale that increments by 5 (i.e., 10, 15, 20, 25, …, 45, 50) would be a good choice as it covers the entire range of the data and allows for easy placement of the box-and-whisker plot points.