Question

calculati media aritmetica ponderata a numerelor :
a ) 2 supra 5 si 3 supra 5 cu ponderiile 3 si 5
b) 3 supra 5 , 2 , 13 supra 7 cu ponderiile 3 , 2 , 4 .
c) 2,5 ; 0 , (3) si 3 intregi si 1 supra 5 cu ponderiile 4 , 12 si 5

Answer 1

(2/5 ×3 +3/5 ×5)/(3+5)=
=(6/5+3)/8=(21/5)/8=21/40
(3/5 ×3 +2×2+13/7 ×4)/(3+2+4)=
=(9/5 +4+52/7 ×4)/9=
=[(63+140+260)/35]/9=
=(463/35)/9=
=463/315
(2,5 ×4 +0,(3)×12+3 1/5 ×5)/(4+12+5)=
=(10 +1/3×12+16/5 ×5)/21=
=(10 +4+16)/21=
=30/21=10/7