Question

Media aritmetica a trei numere este 14,5. AFlati cele trei numere stiind ca media aritmetica a primelor doua numere este 16,256, iar al doilea numar este de trei ori mai mare decat primul.

Answer 1

ma=(a+b+c)/3=14,5 ⇒ a+b+c=14,5×3=43,5 ⇒ a+b+c=43,5
ma=(a+b)2=16,256 ⇒ a+b=32,512        
 b=3a                        
 daca a+b+c=43,5  si a+b=32,512  ⇒ 32,512+c=43,5    c=43,5-32,512    ⇒c=10,988                          
daca a+b=32,512  si b=3a ⇒ a+3a=32,512    4a=32,512    a=32,512/4 ⇒a=8,128                       
  daca b=3a = 3×8,128 = 24,384 ⇒ b=24,384                         

Answer 2

Ma(a,b,c)=a+b+c. a=? b=? c=?
—-–--- =14,5
3

Ma(a,b)=a+b
—– =16,256
2
b=3a

Ma(a,b,c)=14,5·3
a+b+c=43,5

Ma(a,b)=16,256·2
a+b=32,512

Ma(a,b,c)=32,512+c=43,5
32,512+c=43,5
c=43,5-32,512

c=10,988

a+b=32,512
a+3a=32,512
4a=32,512
a=32,512:4

a=8,128

b=3a
b=3·8,128

b=24,384

v: a+b+c=43,5
8,128+24,384+10,988=32,512+10,988=43,5