设X是一随机变量,<imgwidth="17"height="25"v:shapes="_x0000_i1298"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image471.png">为任意实数,<imgwidth="41"height="21"v:shapes="_x0000_i1299"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image473.png">是<imgwidth="19"height="17"v:shapes="_x0000_i1300"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image316.png">的数学期望,则()
①
<imgwidth="184"height="26"v:shapes="_x0000_i1301"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image476.png">
②
<imgwidth="183"height="26"v:shapes="_x0000_i1302"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image478.png">
③
<imgwidth="183"height="26"v:shapes="_x0000_i1303"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image480.png">
④
<imgwidth="100"height="26"v:shapes="_x0000_i1304"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image482.png">