In 1971, the average price of gasoline was $0.36 per gallon. In 2020, the average price of gasoline was $2.32 per gallon. a. What is the percent increase, rounded to the nearest whole number, in the cost of a gallon of gasoline from 1971 to 2020? b. What is the percent decrease, rounded to the nearest whole number, in the cost of a gallon of gasoline from 2020 to 1971? 2. Last year, DeKalb Middle School had 140 7 thgraders. The number of 8 thgraders was 125% of the number of 7 thgraders. How many 8 thgraders were there last year? 3. Find the balance of a savings account at the end of 4 years if the interest earned each year is 5.5%. The principal is $700.

1. a. 544%

b. 84%

2. 175

3. $867.18

Step-by-step explanation:

1. a.2.32-0.36=1.96

1.96/0.36=5.44

5.44*100=544

b. 1.96/2.32=0.84

0.84*100=84

2. let x = # of 7th graders

let y = # of 8th graders

y is 125% of x

y=1.25x

x=140

y=1.25*140

y=175

3. A=P(1+r)^t

A=700(1+0.055)^4

A=867.18

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.

answer: what is the question you're trying to ask?

step-by-step explanation: