The actual height of the Gateway Arch in St. Louis is 630 feet. A scale model of the arch is 9 inches tall. Which statement(s) are true? A. The scale of the model is 1 in.:70 ft.
B. The scale of the model is 1 in.:90 ft.
C. The scale factor is 1:630.
D. The scale factor is 1:840.

D. The scale factor is 1:840

Step-by-step explanation:

Make 630 ft into inches, so 7560

Then make it 9/7560, which simplifies to 1/840

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.