# Size Estimates With Maximum (Loops)

This is a followup to Part 1 Size Estimates Vectorized.

Create a new version of your `mass_from_length_theropoda()`

function from Part 1 of Size Estimates Vectorized called `mass_from_length_max()`

. This function should only calculate a mass if the value of `length`

passed to the function is less than 20. If `length`

is greater than 20 return `NA`

instead. Use `sapply()`

and this new function to estimate the mass for the `theropoda_lengths`

data from Size Estimates Vectorized.

*Expected outputs for Size Estimates With Maximum:*

*1*