问一base 题

shiyiming

Which program does not contain an error?

proc report data=sasuser.houses nowd;
   column style bedrooms baths;
   define style / order;
   define bedbathratio / computed format=4.2;
   compute bedbathratio;
      bedbathratio=baths.sum/bedrooms.sum; endcomp;
run;

proc report data=sasuser.houses nowd;
   column style bedrooms baths BedBathRatio;
   define style / order;
   define bedbathratio / order format=4.2;
   compute bedbathratio;
      bedbathratio=baths.sum/bedrooms.sum; endcomp;
run;

proc report data=sasuser.houses nowd;
   column style bedrooms baths BedBathRatio;
   define style / order;
   define bedbathratio / computed format=4.2;
   compute bedbathratio;
      bedbathratio=baths.sum/bedrooms.sum; endcomp;
run;

proc report data=sasuser.houses nowd;
   column style bedrooms baths BedBathRatio;
   define style / order;
   define bedbathratio / computed format=4.2;
   compute bedbathratio;
      bedbathratio=baths/bedrooms;
   endcomp;
run;

Correct answer: c

Program c correctly specifies a computed variable in the COLUMN statement, defines the variable in a DEFINE statement, and computes values using the form variable-name.statistic in a compute block.

求指教，另外几个选项错在那里

shiyiming

column语句就列出所有变量，包括旧变量和新计算的变量，故A不对。
B中，define bedbathratio / order format=4.2; 因为要计算bedbathratio的值，故后面的选项就用computed，这和C比较便可看出。
D中，bedbathratio=baths/bedrooms;如果要在compute模块中用某变量计算新的变量，则要在要分析的旧变量之后加入一个统计符号，默认为.sum。
并不是什么求和的意思。对于变量如何计算，还要看具体的表达式。回答完毕！