gotchu
i had to edit it on my laptop with the marker tool so be nice ik the handwriting suckssss
i'll write the points for you here tho:
(-2,-12)
(-1,-6)
(0,-3)
(1,-1.5)
Im going to guess you want a sinusoidal function. Its been a while but I can tell you most of it
(443-28)/2 is the amplitude
28 minutes is the period
40-28 is the horizontal shift
(443-28)/2+28 is the vertical shift
5 because they would most likely want a high amount of coins it's common sense. But if they were very strategic they'd probably also pick 3 but most of the time the value expected would be 5.