arrayAverageSum.js

// Program a function sumAverage(arr) where arr is an array containing arrays full of numbers, for example:

// sumAverage([[1, 2, 2, 1], [2, 2, 2, 1]]);
// First, determine the average of each array. Then, return the sum of all the averages.

// All numbers will be less than 100 and greater than -100.
// arr will contain a maximum of 50 arrays.
// After calculating all the averages, add them all together, then round down, as shown in the example below:
// The example given: sumAverage([[3, 4, 1, 3, 5, 1, 4], [21, 54, 33, 21, 77]]), the answer being 44.

// Calculate the average of each individual array:
// [3, 4, 1, 3, 5, 1, 4] = (3 + 4 + 1 + 3 + 5 + 1 + 4) / 7 = 3
// [21, 54, 33, 21, 77] = (21 + 54 + 33 + 21 + 77) / 5 = 41.2
// Add the average of each array together:
// 3 + 41.2 = 44.2
// Round the final average down:
// Math.floor(44.2) = 44
// import math
// math.floor(44.2) = 44



const sumAverage = (arr) => {

    const result = arr.map(e => e.reduce((acc,val) => acc + val,0)/e.length).reduce((acc,val) => acc + val ,0);
  
    return Math.floor(result);
}


console.log(sumAverage([[3, 4, 1, 3, 5, 1, 4], [21, 54, 33, 21, 77]]));



//cw's

function sumAverage2(arr) {
    return Math.floor(arr
            .map(e => e.reduce(sum) / e.length)
            .reduce(sum));
  }
  
  const sum = (a, b) => a + b;