Garrett throws a dart at a circular dart board. The dart board has a radius of 18 inches, and the bull’s eye in the center of the dart board has a radius of 4 inches. What is the probability that a dart thrown at random within the dartboard will hit the bull’s eye? Round your answer to the nearest tenth, if necessary.

Question

hartnn · Answer

Find the area of the board (this will be your sample space)
and area covered by the bull's eye (this will be numerator for calculating probability)

tester97 · Answer

How would i do that?

hartnn · Answer

area of circle = $\Large \pi r^2$

hartnn · Answer

for the board, radius = 18
for the bull's eye, radius = 4

tester97 · Answer

so i would do it like this? $$\frac{ 4^2\pi }{ 18^2\pi }$$

hartnn · Answer

yes, correct.

pi gets cancelled out

hartnn · Answer

if you want your final answer in %, then multiply the above result by 100

tester97 · Answer

so this? $$\frac{ 4 }{ 18 }\times100?$$

hartnn · Answer

no...
did you ignore the squares ?
$\Large \frac{ 4 ^2}{ 18^2 }\times100$

tester97 · Answer

Oh yea sorry i forgot

tester97 · Answer

but i got 4.93 is that right?

hartnn · Answer

4.938% or 4.94 %
yes thats correct!

tester97 · Answer

Thanks Hartnn ;)

hartnn · Answer

welcome ^_^