Answer:
A - Plot the points on a graph, have the x-axis be Time and y-axis be Height
B - 3 am
C - 15 meters
D - from 7 am to 11 am ship can't enter the harbor
Explanation:
A - (1, 12.5), (2, 14.3), (3, 15), (4, 14.3), (5, 12.5), (6, 10), (7, 7.5), (8, 5.7), (9, 5), (10, 5.7), (11, 7.5), (12, 10), (13, 12.5), (14, 14.3), (15, 15)
B - Look at the table at 3 am, that's the highest height
C - Same as A
D - Anything 7.5 meters or below