Unit Rates
Proportional or Not?
Constant of Proportionality
Comparing Proportions
Using Proportional Reasoning
100
A unit rate tells you what?
How much/many for ONE.
100
Not proportional.
100
The equation y=4x represents a proportional relationship. What is the constant of proportionality?
k = 4
100
Does the graph represent a proportional relationship?
How can you tell? (Give 2 reasons)
Yes.
It is a straight line that goes through (0,0).
100
If Frank can walk 2.5 miles in 40 minutes, how long will it take him to walk 4 miles?
64 minutes, or 1 hour and 4 minutes
200
Marley drove 252 miles in 3 1/2 hours. How fast did he drive, in miles per hour?
72 miles per hour
200
Proportional.
200
What is the constant of proportionality?
k = 1.25
200
Does the graph represent a proportional relationship?
No. The line does not go through (0,0).
200
Kyra bought 4 dozen eggs for $7.25. How much would 12 dozen eggs cost?
$21.75
300
Krissy bought 5 pounds of apples for $2.75. What is the cost per pound?
$0.55 per pound
300
Proportional.
300
What is the constant of proportionality?
k = 5
300
Choose one point on the graph. What does it represent in this situation?
x is the number of square feet
y is the total cost
Example: 30 square feet cost $45
300
Josh said that the proportional relationship shown in the table below can be represented by the equation y = 2/3x. Is this correct? Why or why not?
Not correct.
The equation should be y = 1.5x
400
Tanya bought 7 paperback books for $45.50. What was the average cost per book?
$6.50 per book
400
Not proportional.
400
What is the constant of proportionality?
k = 15
400
What does the ordered pair (6, 276) represent on the graph?
After 6 hours of driving you are 276 miles from home.
400
What is the value of y when x = 5?
y = 60 when x = 5.
500
Maria bought 5 paperback books for $32.50. If Jim bought 2 paperback books for $13.50, whose purchase is the better buy?
Maria
500
Proportional.
500
What is the constant of proportionality?
k = 1.14
500
Who was traveling at a faster speed?
Bill's speed was faster.
After 1 hour, Bill was 55 miles from home. After 1 hour, Kevin was only 45 miles from home.
500
Write an equation that represents the proportional relationship shown below.
y = 47x