For each of the following situations, is the percent of change between 20% and 30%?

a) A $12 cost increases to $15
b) A boys height increases from 52 inches to 61 inches
c) The temperature falls from 3 degrees to 2 degrees.

  a) yes

  b) no

  c) no

Step-by-step explanation:

a) The percentage change from 12 to 15 is ...

   (15/12 -1)·100% = 1/4·100% = 25% . . . . between 20% and 30%

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b) The height increased by 61-52 = 9 inches. 20% of 52 inches is 10.4 inches, so the increase was less than 20%.

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c) The increase was negative, so was not between two positive values.

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In summary ...

  a) yes, 25% is between 20% and 30%

  b) no, 17.3% is NOT between 20% and 30%

  c) no, -33.3% is NOT between 20% and 30%

A percentage change can be calculated from ...

  ((new value)/(old value) -1) × 100%

125 yards

step-by-step explanation:

i take 75 plus 50.

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.