3:5的后项加5,要使比值不变,前项应加( )
数据1,2,3的平均数是( )A.6 B.3 C.2
数据1,2,3,4,5,6,7,8,9,10,11的平均数是( )。A.4 B.5 C.6
数据1,9,10,13,14,6,8,12,8的平均数为( )A.1 B.9 C.3
数据1,0,4,3,7,8,9的平均数是( )A.3 B.2 C.4
8642097531,6420875319,4208653197,2086431975,864219753的平均数是( )。A.4444455555 B.5555544444 C.4999999995