(b) give an estimate to the nearest hundreds for . explain how you determined your estimate and tell what means in context of the situation.

Hi! hope this helped B(d) is a function of the number of days d since she opened the account.B(0) is the balance at day=0 now, since the length of segment OA is half of the length of segment OB, and the length of segment OB is proportional to the max balance, namely $400, then the segment OA is proportional to 400/2=200