b:head_first_statistics:estimating_populations_and_samples:sampling_distribution_of_means_in_r
######
# sampling distribution of means
######
ss <- 30 # 30 bags of gums
m <- 10 # average # of gums in a bag
va <- 1 #
sd <- sqrt(va) # variance
s.30 <- rnorm(ss, m, sd)
s.30 # no natural numbers
nm.s.30 <- round(s.30,0) # natural numbers
sk <- nm.s.30
sk
m.sk <- mean(sk)
m.sk
v.sk <- var(sk)
v.sk
sd.sk <- sd(sk)
sd.sk
ss <- 100 # size, from 30 to 100
set.seed(101)
iter <- 10000
# means <- c()
means <- rep(NA, iter)
for (i in 1:iter) {
m.bags <- rnorm(ss,m,sd)
nm.bags <- round(m.bags)
means[i] <- mean(nm.bags)
}
length(means)
head(means)
mean.of.means <- mean(means)
var.of.means <- sd(means)^2
sd.of.means <- sd(means)
mean.of.means
var.of.means
sd.of.means
# what textbook explains
mean.of.means.theo <- m
var.of.means.theo <- va / ss
sd.of.means.theo <- sqrt(va/ss)
mean.of.means.theo
var.of.means.theo
sd.of.means.theo
b/head_first_statistics/estimating_populations_and_samples/sampling_distribution_of_means_in_r.txt · Last modified: by hkimscil