4.986精确到百分位约是 ,保留一位小数约是 .
9÷______=75%=______:8==______(填小数)
=______÷______=60%=______:______=______小数.
2.5:______==1.25=25÷______=______%.
3:5==15÷______=______÷75=______(填小数)
4:10==20÷______="______" (填小数).