javascript中怎么求数组的平均值

function sumAverage() {

  let arr = []

  // console.log(arguments)

  //  for (let index = 0; index < arguments.length; index++) {

  //    arr.push(arguments[index]);

  // }

  arr=Array.from(arguments)

// arr=[...arguments]

  arr.pop()//pop从后面删除

  arr.shift()//shift从前面删除

  let sumTotal=0

 // for (let index = 0; index < arr.length; index++) {

 //      let item = arr[index]

 //      sumTotal += item    

 // }

 sumTotal = eval(arr.join('+'))

  return sumTotal/arguments.length

}

let result = sumAverage(...[1, 6, 7, 8, 9, 9, 44, 1, 55, 1])//...展开数组

console.log(result)