Directly Proportional Relationships

What does k represent in the equation y = kx?

• independent variable

• constant of proportionality

• dependent variable

• krispy kreme

The cost of 4 pounds of grapes is $24.36. What is the constant of proportionality that relates cost in dollars, y, to the number of pounds of grapes, x?

• 6.09

• 20.36

• 8.12

• 28.36

What is the constant of proportionality (in miles per hour) based on the table?

• 45

• 90

• 135

• 2

A grocery store sells sliced turkey. The graph shows the relationship between the weight of the sliced turkey and the total cost of the sliced turkey. Two points, R and W, are labeled on the graph shown below.

• Point R means that the unit rate is $10.00 per

  pound.

• Point R means that the unit rate is 4 pounds

  per dollar.

• Point W means that the unit rate is $2.50 per

  pound.

• Point W means that the unit rate is 2.5 pounds

  per dollar.

The amount of money earned on a job is directly proportional to the number of hours worked.  If $70.00 is earned in 5 hours, how much money is earned in 22 hours of work?

• $2

• $308

• $1.57

• $265

Two quantities are ​ (a)   if the ratios comparing them are equivalent.

• proportional

• nonproportional

• constant of proportionality

• proportion

Answer the following questions.

c

d

g

i

f

10,500

10

1,500

y=10x

yes

y=4500x

100

y = 1500x

4500

no

Which situation represents a proportional relationship?

Select the correct answer ○ in each row.

A family makes homemade pickles. They pick the pickles at a rate of 80 pickles per 5 jars. Which answer choices best represent packing y pickles in x jars at that rate? Select TWO correct answers.

The table is​ ​ (a)   , because it ​ (b)   a constant ratio.

If so, what is the constant of proportionality?​ (c)  

• non-proportional

• proportional

• does not have

• has

• no constant

• k=14

Answer explanation

A proportional relationship means that two quantities maintain a constant ratio. In this case, the relationship does not exhibit a constant ratio, hence the answer is No.