Given a cone with a volume of 288 and height 7 in., find the base radius of the cone. Use 3.14 for pi. Round your answer to the tenths place.

A. 2.4
b. 2.8
c. 3.5
d. 6.3

i was thinking D

Question

Given a cone with a volume of 288 and height 7 in., find the base radius of the cone. Use 3.14 for pi. Round your answer to the tenths place.

A. 2.4
b. 2.8
c. 3.5
d. 6.3

i was thinking D

igreen · Answer

$V = \dfrac{1}{3} \pi r^2 h$

Plug in what we know:

$288 = \dfrac{1}{3}(3.14)(r^2)(7)$

igreen · Answer

Yep, I got 6.3 too.

igreen · Answer

$288 = 7.32666667r^2$

$39.3084622 = r^2$

$r = \sqrt{39.3084622}$

$r \approx 6.3$

anonymous · Answer

ok thank you. i just wasnt sure bc when i plugged 6.3 in for the radius, i was getting 290. i didnt know if that was good enough to assume that 6.3 was correct. but thank you so much @iGreen