first, we need to put the numbers in order
12,15,15,18,20,29,33,42
the median is the middle number...
notice that have an even number of numbers...u have 8 numbers....when u have an even number of numbers, to find the median, take the 2 middle numbers and divide by 2.
median = (18 + 20) / 2 = 38/2 = 19
** if u would have had an odd number of numbers, then u will only have one middle number and that would be ur median