Question

problem 10: spiral review

original price	sale price
$25	$20
$35	$30

aditis attic is having a $5 off sale.
is the relationship between original price and sale price proportional?

yes no

Explanation:

Step1: Define proportional relationship

A proportional relationship follows $y = kx$, where $k$ is a constant ratio of $y$ to $x$.

Step2: Test first data pair

Calculate ratio of sale to original price:
$\frac{10}{15} = \frac{2}{3}$

Step3: Test second data pair

Calculate ratio of sale to original price:
$\frac{20}{25} = \frac{4}{5}$

Step4: Compare ratios

$\frac{2}{3}
eq \frac{4}{5}$, so no constant $k$.
Alternatively, note the relationship is $y = x - 5$, which is a linear (not proportional) relationship (it does not pass through the origin).

Answer:

No