a) To find the median of the data set {5, 13, 16, 9, 12, 13}, we first need to arrange the numbers in ascending order:
5, 9, 12, 13, 13, 16
Since the data set has an even number of values, the median is the average of the two middle numbers. In this case, the two middle numbers are 12 and 13. Therefore, the median is:
Median = (12 + 13) / 2 = 25 / 2 = 12.5
b) To find the median of the data set {73, 65, 81, 90, 125, 67, 90, 90, 84}, we first arrange the numbers in ascending order:
65, 67, 73, 81, 84, 90, 90, 90, 125
Since the data set has an odd number of values, the median is the middle number. In this case, the middle number is 84. Therefore, the median is:
Median = 84