Can someone help? 20 points!

a)
V = [tex]\frac{4}{3} \pi r^{3}[/tex]
905 = [tex]\frac{4}{3} \pi r^{3}[/tex]
2715 = 4π r³
[tex]\frac{2715}{4\pi } = r^{3}[/tex]
216 = r³
[tex]\sqrt[3]{216} = \sqrt[3]{r^{3} }[/tex]
6 = r
b)
[tex]i = (\frac{p1}{p2} )^{\frac{1}{n}} - 1[/tex]
[tex]i = (\frac{200,000}{3,000} )^{\frac{1}{(2012-1945}} - 1[/tex]
[tex]i = (\frac{200}{3} )^{\frac{1}{(67}} - 1[/tex]
i = (66.67)⁰¹⁵ - 1
i = 1.065 - 1
i = 0.065
i = 6.5%
Answers: r = 6, i = 6.5%