October 11, 2013
2-3 proportional relationships and
graphs
October 11, 2013
You can tell if a graph is
proportional by:
1) straight line
2) line goes through
origin (0,0)
3) All ratios reduce to
same thing. (Constant of
proportionality)
October 11, 2013
For this graph,
constant of
proportionality is 3.
So equation would be:
y=3x
y = cost
x = weight in lb.
If I bought 50 pounds, I
would pay: 3(50)= $150.
October 11, 2013
Speed of 3 different race cars
1) Does each race car
show a proportional
relationship?
2) What is the equation
for each race car?
3) What is the constant
of proportionality for
each car?
4) Draw a line that's
faster than all 3 cars.
October 11, 2013