The simplest artificial neuron is the _____.

How many main functions exist in the tidyr package for tidying data?

________ level plotting functions in R start a new plot.

Which function carries out a chi-square test?

Which of the following commands declares the current plot as unused?

Which of the following is the symbol for the standard normal probability density function (PDF)?

How to find out whether the means of 2 groups are equal to each other or not? 

The Gaussian distribution is the most common probability distribution to work with.

The filter() function is similar to the existing subset() function in R but is quite a bit faster.

Explain the output of the code snippet.

> f <- function(num) {
+ hello <- "Hello, world!\n"
+ for(i in seq_len(num)) {
+                    cat(hello)
+ }
+                    chars <- nchar(hello) * num
+                    chars
+ }
> meaningoflife <- f(3)
> print(meaningoflife)