标题: 跟crakman做sas base认证试题(46) [打印本页] 作者: shiyiming 时间: 2010-11-12 23:30 标题: 跟crakman做sas base认证试题(46) From crackman's blog on Baidu
<p><font size="4">46.Given the SAS data set WORK.ONE: <br>
<br>
Obs Revenue2008 Revenue2009 Revenue2010<br>
--- ----------- ----------- -----------<br>
1 1.2 1.6 2.0<br>
<br>
The following SAS program is submitted: <br>
<br>
data WORK.TWO;<br>
set WORK.ONE; <br>
Total=mean(of Rev:);<br>
run;<br>
<br>
What value will SAS assign to Total?</font></p>
<p><font size="4"> A. 3 <br>
B. 1.6<br>
C. 4.8<br>
D. The program fails to execute due to errors. <br>
<br>
Answer: B</font></p>
<p><font size="4">本题考察的是变量简写的问题。<br>
TOTAL=MEAN(OF REV:) 等价于 TOTAL=MEAN(OF REVENUE2009-REVENUE2010) 或者TOTAL=MEAN(REVENUE2008,REVENUE2009,</font></p>
<p><font size="4">REVENUE2010).<br>
REV:表示是以REV开头的所有变量。<br>
可以考虑一下,如果是REV结尾的所有变量,该如何操</font></p> <a href="http://hi.baidu.com/crack%5Fman/blog/item/10de695d16b18c3a2934f0c1.html">阅读全文</a>