Smith fills the family pool with water for the summer. After two hours, the water has reached a depth of 2.5 feet. After three hours, the water level has risen to 3 3/4 feet. If the relationship between time and water depth is proportional, what is the constant of proportionality?
Look at it as 2 ordered pairs,
(2, 2.5) and (3 , 3.75)
slope = (3.75 - 2.5)/(3-2) ft/hr
= 1.25 ft/h
your equation relation depth and time would be
d = 1.25t , where d is the depth in ft, and t is time in hours