Pertanyaan: Cari rata-rata proporsional antara 49 & 64? Pilihan: (A) A) 59 (B) B) 61 (C) (C) 56 (D) D) 65 (E) (E) 67 Pikiran acak:
Rumus = √a×b A = 49 dan B = 64 √49×64 = 7 × 8 = 56 Jawaban akhir: (C).