Răspuns :
4 .2/a=5/b=7/140
b=140*5:7
b=100
a=2*100:5
a=40
3.Nu stiu =>12/100*228=34,56
b=140*5:7
b=100
a=2*100:5
a=40
3.Nu stiu =>12/100*228=34,56
x-nr de persoane care au participat la sondaj
12/100 × x=228
3/25 × x=228
x= 228 ÷ 3/25
x= 228 × 25/3
x=5700/3
x=1900
12/100 × x=228
3/25 × x=228
x= 228 ÷ 3/25
x= 228 × 25/3
x=5700/3
x=1900