Unfortunately, when I dropped in, Doctor Li _____ for Beijing to join in the fight again SARS, so we only had time for a few words. A. just left B. has just left C. is just leaving D. was just leaving
【简答题】加权算术平均数不但受变量值大小的影响,而且也受变量值出现的次数多少的影响。因此,下列情况中对平均数不发生影响的是( )。 A. 变量值比较小而次数较多时 B. 变量值较大而次数较小时 C. 变量值较大而次数较多时 D. 变量值出现的次数相等时A. 15. 加权算术平均数不但受变量值大小的影响,而且也受变量值出现的次数多少的影响。因此,下列情况中对平均数不发生影响的是( )。...