A.計(jì)算三門課程成績的平均分 B.計(jì)算三門課程成績的標(biāo)準(zhǔn)差 C.計(jì)算三門課程成績的方差 D.計(jì)算三門課程成績的總分
A.Both file iprovide cases B.External file is keyed table C.Working data file is keyed table D.Indicate case source as variable
A.待合并的兩個(gè)數(shù)據(jù)文件的數(shù)據(jù)結(jié)構(gòu)完全相同 B.可以是兩個(gè)完全不相干的數(shù)據(jù)文件 C.在兩個(gè)數(shù)據(jù)文件中,數(shù)據(jù)含義相同的數(shù)據(jù)項(xiàng)最好起相同的變量名 D.待合并的兩個(gè)數(shù)據(jù)文件的個(gè)案數(shù)相同