Math 7A Chapter 5: Proportional relationships
Worksheet 6: Equations of proportional relationships
Name:___________________
Date: ___________ Pd: ___
For each proportional relationship below, find the constant of proportionality k. Using this value,
write an equation that represents the situation.
1.
2.
Pictures, x
3
4
5
Profit ($), y
27
36
45
A: Find the constant of proportionality k,
or the unit rate.
A: Find the constant of proportionality k,
or the unit rate.
B: Write the equation of this relationship.
B: Write the equation of this relationship.
3. If y varies directly with x, write the equation for this relationship if y = 35 when x = 7.
4. Using the equation from Problem 3, what is the value of y when x = 4?
5. Al’s Produce sells 7 ears of corn for $1.50. Maggie’s Market sells 13 ears of corn for $2.85.
Round your answers to the nearest cent.
a. For Al’s Produce, what is the constant of proportionality between the cost and the number
of ears of corn?
b. For Al’s Produce, write an equation that represents this relationship. Let C = cost and N =
ears of corn.
c. For Maggie’s Market, what is the constant of proportionality between the cost and the
number of ears of corn?
d. For Maggie’s Market, write an equation that represents this relationship. Let C = cost and
N = ears of corn.
e. Which store charges more per ear of corn? Explain your answer.