Final answer:
The average (mean) of the given data set is 15.06.
Step-by-step explanation:
The average (mean) of the given data set is 19 + 27.9 + 24.7 + 9.2 + 15.2 + 5.1 + 1.8 + 26.6 + 7 = 135.5. To find the average, you sum up all the data values and then divide it by the total number of values. In this case, there are 9 values in the data set, so the average is 135.5 divided by 9, which equals 15.06 (rounded to two decimal places).