explain this: mean(arrayfun(@(x) abs(x) > 1.96, randn(10^5, 1))) in matlab

The code generates an array with 100,000 random numbers sampled from a standard normal distribution using randn(10^5, 1). Then, arrayfun applies the anonymous function @(x) abs(x) > 1.96 to each element of the array and returns an array of the same size with the logical values true or false of whether or not the absolute value of each element of the original array is greater than 1.96.

Finally, mean is used to calculate the proportion of true values in the logical array. This means the output represents the proportion of random numbers from the standard normal distribution that have an absolute value greater than 1.96, which should be approximately 0.05 or 5% based on the properties of the normal distribution.