Question

Rachel is getting a sundae where the cost is proportional to the weight of the sundae she makes. Last time Rachel went she bought a 12-ounce sundae for $4.20. This time she buys a 17-ounce sundae. Let c be the cost of the sundae. Set up and solve a proportion for c.( Please show your work on how this problem is solved so i can understand it.)

Answer 1

12 Oz sundae is $4.20

The cost is given by the following eqation

$c=\frac{\text{Last time price}}{\text{Last time weight}}\cdot w$

where,

c is the cost of the sundae

w is the weight of the sundae

last time price = $4.20

last time weight = 12 Oz

Solving:

$c=\frac{4.20}{12}\cdot w$

Simplify

$c=0.35\cdot w$

if the sundae is 17 Oz , then the price would be: $5.95

$c=0.35\cdot17=5.95$