Session Ready
Exercise

Removing NAs

We previously computed the average of na_example using mean(na_example) and obtain NA. This is because the function mean returns NA if it encounters at least one NA. A common operation is therefore removing the entries that are NA and after that perform operations on the rest.

Instructions
100 XP

Write one line of code to compute the average, but only for the entries that are not NA making use of the ! operator before ind. (Remember that you can use help("!") to find out more about what ! does.)