设<imgwidth="75"height="22"v:shapes="_x0000_i1220"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb10.files/image314.png">是来自正态总体<imgwidth="60"height="22"v:shapes="_x0000_i1221"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb10.files/image290.png">的样本,则<imgwidth="98"height="40"v:shapes="_x0000_i1222"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb10.files/image316.png">服从的分布为()
①
<imgwidth="37"height="22"v:shapes="_x0000_i1223"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb10.files/image318.png">
②
<imgwidth="58"height="22"v:shapes="_x0000_i1224"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb10.files/image320.png">
③
<imgwidth="63"height="40"v:shapes="_x0000_i1225"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb10.files/image321.png">
④
<imgwidth="63"height="40"v:shapes="_x0000_i1226"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb10.files/image321.png">