Answer:
25
Explanation:
20, 30, 40, 10, 15, 25, 35
Put the data in order from smallest to largest
10,15,20, 25,30,35, 40
The median is the middle
There are 7 pieces of data so the 4th piece is in the middle
10,15,20, 25, 30,35, 40
25 is in the middle so it is the median