Pelan

Kalkulator Purata Berwajaran

Kalkulator ini mencari purata apabila sesetengah nilai lebih berat daripada yang lain, seperti markah dengan wajaran berbeza. Masukkan nilai dan wajarannya; ia mendarab, menambah dan membahagi sambil menunjukkan setiap langkah.

Pisahkan nilai dengan koma atau ruang.
Wajaran boleh berupa peratusan, kredit atau kekerapan.

Keputusan

Masukkan nilai dan tekan Kira untuk melihat keputusan.

Formula

xˉw=∑wixi∑wi\bar{x}_w = \frac{\sum w_i x_i}{\sum w_i}

Multiply each value by its weight, add the results, then divide by the total weight.

Cara menggunakan kalkulator ini

  1. Enter the values, then their weights in the same order.
  2. Weights do not need to add up to 1 or 100: the calculator divides by their total.
  3. Press Calculate to see the weighted average and the working.

Contoh berserta jalan kerja

Marks 80, 90 and 70 with weights 2, 3 and 5

80 × 2 + 90 × 3 + 70 × 5 = 160 + 270 + 350 = 780.

The weights add up to 10, so the weighted average is 780 ÷ 10 = 78.

Percent weights: 72 (40%) and 85 (60%)

72 × 40 + 85 × 60 = 2880 + 5100 = 7980.

7980 ÷ 100 = 79.8.

Kesilapan biasa

  • Taking the ordinary mean, which treats every value as equally important.
  • Dividing by the number of values instead of the total weight.
  • Listing weights in a different order from the values.

Soalan lazim

How do you calculate a weighted average?

Multiply each value by its weight, add these products, and divide by the sum of the weights.

Do the weights have to add up to 100%?

No. Dividing by the total weight takes care of it: weights 2, 3, 5 work the same as 20%, 30%, 50%.

When is a weighted average used?

Course grades with weighted assignments, grade point averages with credit hours, and averaging prices bought in different quantities.