A candle maker uses a mold to make candles like the one shown below.
(photo attached)

The height of the candle is 13 cm and the
circumference of the candle at its widest measure is
31.416 cm. Use modeling to approximate how
much wax, to the nearest cubic centimeter, is
needed to make this candle.

340 cm3  

Step-by-step explanation:

Hi, to answer this question we have to apply the next formulas:  

Circumference = 2π radius

Replacing with the circumference value and solving for r:

31.416 =2π r

31.416 /2π =r

5cm =r

And then:

Volume of a cone = 1/3 x π x radius^2 x height  

Replacing with the values given:  

V = 1/3 π (5)^2 (13) = 340 cm3  

Feel free to ask for more if needed or if you did not understand something.  

a)

$4,000 + $960 = $4,960

She has $4,960 in her account at the end of 3 years

b)

i = Prt

r = i/Pt

r = 960 / 4000 * 3

r = 960 / 12000

r = 0.08

Annual interest rate is 0.08 or 8%

c) If 1% greater then r = 0.09 (9%)

i = Prt

i = $4,000 * 0.09 * 3

i = $1, 080

The different: $1, 080 - $960 = $120

She would have $120 more in her account if the interest rate were 1% greater.