Respuesta :

mhanifa

Answer:

  • 17 1/3 or 17.33

Step-by-step explanation:

Mean of four numbers a, b, c, and d is 8:

  • (a + b + c + d)/4 = 8  
  • ⇒ a + b + c + d = 32

Mean of seven numbers x, y, z, a, b, c and d is 12:

  • (x + y + z + a + b + c + d)/7 = 12

Substitute the sum of 4 numbers:

  • x + y + z + 32 = 7*12
  • x + y + z = 84 - 32
  • x + y + z = 52

Mean of x, y and z is:

  • 52/3 = 17 1/3 or 17.33