Question

Media aritmetica a 4 numere zecimale este 67,15,iar media aritmetica a ultimelor trei numere este 50,12.Aflati primul numar.

Answer 1

(a+b+c+d):4=67,15
a+b+c+d=67,15x4⇒268,6 (suma celor 4 nr)
(b+c+d):3=50,12
b+c+d=50,12x3⇒150,36 (suma ultimelor 3 nr)
a+150,36=268,6
a=268,6-150,36
a=118,24

Answer 2

(x+y+z+t):4=67,15
(y+z+t):3=50,12
x+y+z+t=67,15·4
x+y+z+t=268,6
y+z+t=50,12·3
y+z+t=150,36
x=(x+y+z+t)-(z+z+t)
x=268,6-150,36
x=118,24.