##
## okular ../../EBook/Investment_Science.djvu -p 242 & 
##
RoR = data.frame(month=1:24,
                 percent_ror=c(1.0, 0.5, 4.2, -2.7, -2.0, 3.5, -3.1, 4.1, 1.7, 0.1, -2.4, 3.2, 4.2, 4.5, -2.5, 2.1, -1.7, 3.7, 3.2, -2.4, 2.7, 2.9, -1.9, 1.1))
print(RoR)


## Part (a-b):
##
r_m = mean(RoR$percent_ror)
r_yr = 12*r_m

s_m = sd(RoR$percent_ror)
s_yr = sqrt(12) * s_m
print(c(r_m, r_yr))
print(c(s_m, s_yr))


## Part (c):
##
n = 24
print((sqrt(2) * s_yr^2)/sqrt(n-1))


## Part (d):
##
print(sqrt(23)/sqrt(103))