Gets the type of (excess) kurtosis

## Arguments

- kurtosis
numeric.

## Value

Returns one of 'platykurtic', 'mesokurtic' or 'leptokurtic'.

## Details

Kurtosis is a measure of the tailedness of a distribution. Distributions can be compared
to the Normal distribution by whether their kurtosis is higher, lower or the same as that of the
Normal distribution.

A distribution with a negative excess kurtosis is called 'platykurtic', a distribution
with a positive excess kurtosis is called 'leptokurtic' and a distribution with an excess
kurtosis equal to zero is called 'mesokurtic'.

## Examples

```
exkurtosisType(-1)
#> [1] "platykurtic"
exkurtosisType(0)
#> [1] "mesokurtic"
exkurtosisType(1)
#> [1] "leptokurtic"
```