Respuesta :

Answer:

  • (ax + by + cz)/(a + b + c)

Step-by-step explanation:

  • Average = Sum / Number

In terms of the scores we calculate the sum as:

  • ax + by + cz

The number is the sum of the frequencies:

  • a + b + c

Mean average score is:

  • (ax + by + cz)/(a + b + c)