Answer: 75 cars (choice C)
Step-by-step explanation:
x = 13 represents 1 PM since it is 13 hours after 12:00 AM midnight.
Fast forward another 3 hours and we get to x = 13+3 = 16 to represent 4 PM
Mark 16 on the x axis. Then draw a vertical arrow upward until you get to the parabola. From there, draw a horizontal line to the left until reaching the y axis. See the diagram below.
You should arrive between y = 60 and y = 90. A good estimate is to find the midpoint
midpoint = (a+b)/2 = (60+90)/2 = 150/2 = 75
We estimate that about 75 cars are expected to be parked at 4 PM.