Pole-Vault-Starting-Marks.js

/* For a pole vaulter, it is very important to begin the approach run at the best possible starting mark. This is affected by numerous factors and requires fine-tuning in practice. But there is a guideline that will help a beginning vaulter start at approximately the right location for the so-called "three-step approach," based on the vaulter's body height.

This guideline was taught to me in feet and inches, but due to the international nature of Codewars, I am creating this kata to use metric units instead.

You are given the following two guidelines to begin with: (1) A vaulter with a height of 1.52 meters should start at 9.45 meters on the runway. (2) A vaulter with a height of 1.83 meters should start at 10.67 meters on the runway.

You will receive a vaulter's height in meters (which will always lie in a range between a minimum of 1.22 meters and a maximum of 2.13 meters). Your job is to return the best starting mark in meters, rounded to two decimal places.

Hint: Based on the two guidelines given above, you will want to account for the change in starting mark per change in body height. This involves a linear relationship. (If you're not clear on that, search online for "linear equation.") But there is also a constant offset involved. If you can determine the rate of change described above, you should be able to determine that constant offset.

 */

// solution

const startingMark = bodyHeight =>
  +(bodyHeight * 3.9354 + 3.4681).toFixed(2);