Please help !! add these

The amount spent on food and drink by 20 customers is shown below what is the modal amount spent and the median? 40 25 8 36 18 15 24 27 43 9 12 19 22 34 31 20 26 19 17 28

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Need plz been trying to do it for a long time and still haven’t succeeded