fix: Average Median code cleanup (#1388)

Maths/AverageMedian.js

@@ -9,22 +9,14 @@
  */
 
 const averageMedian = (sourceArrayOfNumbers) => {
-  let numbers = [...sourceArrayOfNumbers]
-  let median = 0
+  const numbers = [...sourceArrayOfNumbers].sort(sortNumbers)
   const numLength = numbers.length
-  numbers = numbers.sort(sortNumbers)
 
-  if (numLength % 2 === 0) {
-    median = (numbers[numLength / 2 - 1] + numbers[numLength / 2]) / 2
-  } else {
-    median = numbers[(numLength - 1) / 2]
-  }
-
-  return median
+  return numLength % 2 === 0
+    ? (numbers[numLength / 2 - 1] + numbers[numLength / 2]) / 2
+    : numbers[Math.floor(numLength / 2)]
 }
 
-const sortNumbers = (num1, num2) => {
-  return num1 - num2
-}
+const sortNumbers = (num1, num2) => num1 - num2
 
 export { averageMedian }