Bash choose between two values but choose one value 4 times more than another

Question

It's simple to call a number between two numbers

echo $( shuf -i 15-16 -n 1 )

or call two numbers using variables

#!/bin/bash
var1=15
var2=16
echo "${var1}${var2}"
exit ;
    sh

Question - is it possible to call number 15 (or $var1 from second example) - 4 times more often than number 16 (or $var2 from second example) ?

Answer 1

Ask shuf for a single value and provide it with input data that contains four times as many 15 than 16 . In bash ,

shuf -n 1 <<<$'15\n15\n15\n15\n16'