eleven students have a math with the average score 65.the difference between the highest and the lowest scores is 20.if the highest and the lowest scores are ig

misal x = jumlah semua nilai, n = jumlah siswa = 11

x = 65.n,
x = 65.11
x = 715

jika tertinggi dan terendah dikeluarkan maka rata2 = 63
(x - (a+b))/(11-2) = 63
           715 - (a+b) = 567
                       a+b = 148,
nilai a tertinggi dan b terendah

a+b = 148
a- b =  20 (+) selisih nilai tinggi rendah
---------------
   2a = 168
     a = 84, nilai tertinggi adalah 84

jumlah skor 11 siswa = 11 x 65 = 715
jumlah skor 9 siswa = 9 x 63 = 567
jumlah skor siswa terendah dan tertinggi = 715 - 567 = 148
skor tertinggi 84 dan terendah 64