Question

Can someone tell me what's the midrange ?

Answer 1

The midrange is average value between the lowest and the highest values of the sequence:
$m= \frac{min+max}{2} = \frac{12+28}{2}= \frac{40}{2}=20$

Answer 2

The midrange will be 16. You cancel out the end numbers until you get to the middle. Number and the middle number is your midrange.