The question is as follows:
Suppose the weight of avocados in a large crate has a distribution with mean 197 grams and standard deviation 7.6 grams. Consider the process of picking 7 avocados at random from the crate and putting them in a bag. Let X be the total weight of the bag. The standard deviation of X is.....
I have attempted to solve using R code: X = sample(sum(rnorm(7,197,7.6)), 999999, replace=TRUE)
then sd(X)
which takes many samples from the sum of a selection of 7 avocados from the normal distribution, to no avail.
EDIT: I have solved it using $\bar{X}$ is $\sigma_\bar{X}=\frac{\sigma_X}{\sqrt{n}}$, where $\sigma_X$ is the standard deviation of $X$ and $n$ is the sample size (sourced from a different answer) but I don't understand what it actually means...