Question

question 16 of 25
stojan has money automatically deposited into a savings account each week. after 2 weeks, he has $14. after 4 weeks, he has $28. the unit rate is measured in dollars per week. what is the constant of proportionality?
a. \\(\frac{1}{7}\\)

b. 6

c. 7

d. 12

Explanation:

Step1: Define proportionality formula

Let $y$ = total savings, $x$ = weeks, $k$ = constant. The relationship is $y = kx$.

Step2: Solve for k using first data

Substitute $y=14$, $x=2$:
$$k = \frac{y}{x} = \frac{14}{2} = 7$$

Step3: Verify with second data

Substitute $y=28$, $x=4$:
$$k = \frac{28}{4} = 7$$
The constant is consistent.

Answer:

C. 7