Answer:
Median = 77
Explanation:
25,24,21,76,78,78,77,90,99
The median of a data set can be thought of as the 'middle' number when they have been ordered from highest to lowest. Hence, this ordering is our first step:
21, 24, 25, 76, 77, 78, 78, 90, 99
Now, the easiest way to find the medium is simply to cancel one number from each side until there is only one left. Hence:
24, 25, 76, 77, 78, 78, 90
25, 76, 77, 78, 78
76, 77, 78
77
The median of this data set is 77
Hope that helps!