The following table shows the monthly charges for subscribing to the local newspaper.

number of months
1
2
3
4
5
total cost ($)
15.25
30.50
45.75
61.00
76.25

identify the independent and dependent variables in the newspaper subscription table.
a.
independent -- total cost
dependent -- number of months
c.
independent -- total cost
dependent -- month of the year
b.
independent -- cost per paper
dependent -- number of months
d.
independent -- number of months
dependent -- total cost

answer: c, the green line

step-by-step explanation:

there is no black line, eliminate b.

simple interest implies periodic payments, but the red line shows no payments, eliminate d.

simple interest has equal payments. if paid say every day, the graph is about a straight line (actually a stairstep).

the yellow line is not straight, eliminate a.

check: the green line is straight, answer is c.

simple interest with positive interest rate gives a straight line sloping up to the right. green line:

g(t) = $100 + ($200-$100) ÷ (20 years) × (t years)

= $100 + (4%/year) × ($100)(t years)

incidentally, the yellow line curving upward represents continuously compounded interest

y = $100 × 2^(t years / (14 assuming the yellow line hits $200 at 14 years. 2^0 is 1, so y(0) = $100; 2^(14/14) is 2, so y(14) = $200.