The range of a set of values is the lowest and highest number of that data set.
First, lets put the numbers from least to greatest.
138, 142, 155, 165, 172, 193
Second, find the lowest and greatest number in the data set.
138 is the lowest and 193 is the highest number in the data set.
Therefore, 138 and 193 is the range.
Best of Luck!