Takes an array of numbers and returns their average, rounded to the thousands place

avgToThsnds.js

const toThsnds = compose(
  multiply(1000),
  Math.round,
  multiply(1/1000)
);

const avgToThsnds = (arr) => compose(
  toThsnds,
  multiply(1/length(arr)),
  reduce(add, 0)
)(arr);

avgToThsnds([100000, 110000, 150000]);