Why is 4 < x < 3 not a true solution?

On a piece of paper graph f(x)=5•(0.4)^x

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

Which graph has figures that can undergo a similarity transformation to justify that they are similar? (obviously not the third one)