Question

Which situation below has the highest constant of

proportionality?
A) 16 ounces of jasmine rice costs $4.80.
B) 32 ounces of white rice costs $6.40
C) 12 ounces of white rice costs $1.20.
D) 9 ounces of brown rice costs $1.80

Answer 1

We need unit rates for all

#A

• 4.80/16
• 0.3

#B

• 6.4/32
• 0.2

#C

• 1.2/12
• 0.1

#D

• 1.8/9
• 0.2

A has highest

Answer 2

• A) k = 0.3

Explanation:

Find the constant of proportionality k in each case and compare

• y = kx

A)

• 16k = 4.80 ⇒ k = 4.80/16 ⇒ k = 0.3

B)

• 32k = 6.40 ⇒ k = 6.40/32 ⇒ k = 0.2

C)

• 12k = 1.20 ⇒ k = 1.20/12 ⇒ k = 0.1

D)

• 9k = 1.80 ⇒ k = 1.80/9 ⇒ k = 0.2

As we see k = 0.3 is the highest one