population.size = 1000000
population.mean1 = 300
population.std1 = 100
population.mean2 = 325
population.std2 = 100
plot.delay = 0.0
sample1.size = 30
sample2.size = 30
numberofsamples = 50

population.data1 = rnorm(population.size,population.mean1,population.std1)
population.data2 = rnorm(population.size,population.mean2,population.std2)
population.mean1 = mean(population.data1)
population.mean2 = mean(population.data2)

par(mfrow=c(3, 1))

# plot histogram with normal curve
par(mar=c(1,1,1,1))
hist(population.data1, col=rgb(1,0,0,0.5), breaks=20, xlab="Reaction Time",main="",xlim = c(1,1000),ylim=c(0,300000)) 
hist(population.data2, col=rgb(0,0,1,0.5), breaks=20, xlab="Reaction Time",main="",xlim = c(1,1000),ylim=c(0,300000),add=T)

abline(a = NULL, b = NULL, h = NULL, v = (population.mean1),col=2)
abline(a = NULL, b = NULL, h = NULL, v = (population.mean2),col=4)

# plot the first sample
sample.data = sample(population.data1,sample1.size,replace = TRUE)
sample.mean = mean(sample.data)
plot(sample.mean,numberofsamples,ylim = c(1,numberofsamples),xlim = c(1,1000))
title(main='Population 1')
Sys.sleep(plot.delay)

abline(a = NULL, b = NULL, h = NULL, v = (population.mean1),col=2)
abline(a = NULL, b = NULL, h = NULL, v = (population.mean2),col=4)

# plot 99 more samples
for (plot.counter in 1:numberofsamples-1)
{
sample.data = sample(population.data1,sample1.size,replace = TRUE)
sample.mean = mean(sample.data)
points(sample.mean,numberofsamples-plot.counter)
Sys.sleep(plot.delay)
}

# plot the first sample
sample.data = sample(population.data2,sample2.size,replace = TRUE)
sample.mean = mean(sample.data)
plot(sample.mean,numberofsamples,ylim = c(1,numberofsamples),xlim = c(1,1000))
title(main='Population 2')
Sys.sleep(plot.delay)

abline(a = NULL, b = NULL, h = NULL, v = (population.mean1),col=2)
abline(a = NULL, b = NULL, h = NULL, v = (population.mean2),col=4)

# plot 99 more samples
for (plot.counter in 1:numberofsamples-1)
{
  sample.data = sample(population.data2,sample2.size,replace = TRUE)
  sample.mean = mean(sample.data)
  points(sample.mean,numberofsamples-plot.counter)
  Sys.sleep(plot.delay)
}