Section C Section C Checkpoint

Problem 1

Here is a piecewise linear model for the water height in feet of a reservoir that supplies water to a nearby town over a 12-month period.

A scatterplot, horizontal, months, 0 to 12, vertical, height of water in feet, 6660 to 6740.
A scatterplot, horizontal, months, 0 to 12, vertical, height of water in feet, 6660 to 6740. points trend downward from months 0 to 3, then upward to month 6, then horizontal to month 7, then downward to month 12.

Select all the true statements.

A
h=-4x+6,676h = \text-4x + 6,676  is a reasonable model for the water level from Months 0 to 3.
B
The slope from Months 3 to 5 is 57 and means that during that time the height of the water increased 57 feet each month.
C
The time is a function of the height of the water.
D
The height of the water is a function of the time.
E
The water height decreased at about the same rate from Months 0 to 3 and from Months 7 to 12.
Show Solution
Solution
A, D, E
Show Sample Response
Sample Response
A, D, E

Problem 2

A large university campus has two bike sharing programs students can pay for each month.

  • Program A advertises that they charge 34 dollars to join and 1 dollar per mile traveled.
  • Program B advertises that their fee to join is less than 50 dollars and that they charge less per mile than Program A.

A graph of line l. Horizontal axis, distance traveled in miles. Vertical axis, cost in dollars.

  1. Which program is represented by line \ell?
  2. If cc is the cost in dollars and mm is the distance traveled in miles for a month, write a possible equation to represent Program B.
Show Solution
Solution
  1. Program A is represented by line \ell.
  2. Any equation with an initial value less than 50 and a rate of change less than 1 dollar per mile. Sample response: c=45+0.25mc=45+0.25m.
Show Sample Response
Sample Response
  1. Program A is represented by line \ell.
  2. Any equation with an initial value less than 50 and a rate of change less than 1 dollar per mile. Sample response: c=45+0.25mc=45+0.25m.