4个自然数,取3个数的平均数加上另一个数,和分别为51,39,43,41,这四个数依次为 , , , .
10÷ == : = (小数)= %
:20==24÷ =80%
3:4==24÷ = %= .(填小数)
75÷ == .
= :10=0.2=10÷ = %.