Find 25 seconds in the table. That's between 20 and 30, right? So, find the median between 19 and 28:
19 + 28
---------- = 23.5
2
That is around 24 deep knee squats per 25 seconds. Now, use the same method for 65 seconds:
51 + 58
---------- = 54.5
2
That is around 55 deep knee squats per 65 seconds.
Now, explain the method using words. You might wanna use the words "average" or "mean" to describe that process above.