已知随机变量[tex=0.857x1.0]KGogyvwDAIJf/iL0H/9wjg==[/tex]的数学期望为[tex=2.357x1.357]y0JP40XwxAEl4j7GgRfsFw==[/tex], 则必有[br][/br][br][/br][br][/br] 未知类型：{'options': ['[tex=7.571x1.571]T43KjubOoy45RZb2iPeGF+uP5WQMxaynLd6ZKRbQfv0=[/tex]', '[tex=8.5x1.286]bh0mtlNGqf/oTV8NRYgTsJ73T1WnzUJDIsN+lOxDZicP9k6L94vzavIEFNTPfIhjR4CjsRMd0vzNs2wnd6r+2w==[/tex]', '[tex=8.0x1.286]bh0mtlNGqf/oTV8NRYgTsGOKyYthWxW/HUq5svhLGXteHM+gfTI1ToF/CeB/lPwO[/tex]', '[tex=10.143x1.286]bh0mtlNGqf/oTV8NRYgTsHnl9VyqfbgZsucWDlfB3g3CnlkOMiok7/w9MloC4OQzToPbMIk1SrjImurQdxIPuQ==[/tex]'], 'type': 102}