The 733 monthly investment gives an effective rate of The 7

The 7.33% monthly investment gives an effective rate of %. The 7.12% semiannually investment gives an effective rate of %.

effective rate,
r = (1 + i/n)^n - 1

a)
i = 7.33/100 = 0.0733
n=12
r = (1 + 0.0733/12)^12 -1
r = (1 + 6.11*10^-3)^12 -1
= 0.0758
= 7.58 %
Answer: 7.58 %

b)
i = 7.12/100 = 0.0712
n=2
r = (1 + 0.0712/2)^2 -1
r = (1 + 0.0356)^2 -1
= 0.0725
= 7.25 %
Answer: 7.25 %