Explicație pas cu pas:
media aritmetica= ma ( prescurtat )
ma = ( a+ b ) : 2 ( sau la 3, 4 depinde cate numere sunt in paranteza )
a) ma= ( 3, 5 + 4 ) : 2 = 7, 5 : 2 =3, 75
b)ma= ( 5+4+9+10 ) : 4 = 28 :4 = 7
c)ma= ( 11+13+12 ) : 3 =36 : 3 = 12
d) ma= ( 8+9+18 ) : 3 = 35 : 3 = 11, ( 6)
e) ma= ( 5+10+15+ 20 ) : 4 = 50 :4 = 12, 5
f) ma = ( 8+9+40 + 12 ) : 4 = 69 : 4 = 17, 25
g)ma= ( 10+15+16 +24 ) :4 = 65 : 4 =16, 25
h) ma = (9+14+13 ) :3 = 36 :3 = 12
i) ma = ( 21+30+40) :3 =91 :3 = 30, (3 )
j)ma = ( 7+9+11+22+33 ) : 5 = 82 :5 = 16, 4