put them in order from the smallest to the largest:
110, 125, 138 , 144, 152,153,162, 163,164, 174, 174, 175, 177,180,183,185, 186,187, 194,195, 196,198
find the 2 middle numbers, in this case 174 & 175
the median is the average of those 2 numbers:
(174 + 175 )/2 = 174.5
the median = 174.5