## empty plot with appropriate ranges

plot(0,0, type = "n",
     xlim = c(25, 55),
     ylim = c(0,.25),
     xlab = "x",
     ylab = "Density")

## the two normal densities plotted in an interval of
## plus/minus 3*sigma around mu.

mu <- 41
sigma <- 2
curve(dnorm(x,mu,sigma), mu-3*sigma, mu+3*sigma, add=TRUE)

mu <- 40
sigma <- 5
curve(dnorm(x,mu,sigma), mu-3*sigma, mu+3*sigma, add=TRUE)

## vertical line indicating true mean
abline(v=40, lty="21")