text: //#dnn_ctr479_ViewSVKQHocPhan_rptKQHocPhan_trDaDanhGia_0 > td:nth-child(12)
  //#dnn_ctr479_ViewSVKQHocPhan_rptKQHocPhan_trDaDanhGia_0 > td:nth-child(4)
  let list_grade = []
  let tin_chi = []
  let pending = true
  for (let i = 0; pending == true; i++) {
      let select_name = '#dnn_ctr479_ViewSVKQHocPhan_rptKQHocPhan_trDaDanhGia_' + i + ' > td:nth-child(12)';
      let elem = $(select_name)
      let select_tinchi = '#dnn_ctr479_ViewSVKQHocPhan_rptKQHocPhan_trDaDanhGia_' + i + ' > td:nth-child(4)';
      let elem_tinchi = $(select_tinchi)
  
      if (elem.length > 0) {
          list_grade.push(parseFloat(elem[0].innerText));
          tin_chi.push(parseFloat(elem_tinchi[0].innerText));
          console.log(parseFloat(elem[0].innerText))
      } else {
          pending = false
      }
  }
  let sum = 0
  list_grade[14] = 7
  list_grade[16] = 8
  let tong_tin_chi = 0.0
  for (let i = 0; i < list_grade.length; i++) {
      sum += list_grade[i] * tin_chi[i]
      tong_tin_chi += tin_chi[i]
  }
  console.log(list_grade);
  console.log('sum :' + sum);
  console.log('avg :' + sum / tong_tin_chi);
  