设随机变量<imgwidth="19"height="17"v:shapes="_x0000_i1242"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image266.png">的分布函数为<imgwidth="132"height="75"v:shapes="_x0000_i1243"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image335.png">,则<imgwidth="48"height="21"v:shapes="_x0000_i1244"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image337.png">()
①
<imgwidth="57"height="35"v:shapes="_x0000_i1245"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image339.png">
②
<imgwidth="55"height="35"v:shapes="_x0000_i1246"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image341.png">
③
<imgwidth="108"height="35"v:shapes="_x0000_i1247"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image343.png">
④
<imgwidth="64"height="34"v:shapes="_x0000_i1248"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image345.png">