押题试卷一
卷面总分:100分
试卷年份:2022.10
是否有答案:有
作答时间: 150分钟
设总体X的分布律为P{X=1)=p,P{X=0)=1—P,其中0<p<1.设X1,X2,…,Xn为来自总体的样本,则样本均值
的标准差为( )
Fatal error: Uncaught Error: Call to a member function fetch_array() on boolean in /www/wwwroot/www.shzkw.org/phpcms/libs/classes/db_mysqli.class.php:153
Stack trace:
#0 /www/wwwroot/www.shzkw.org/phpcms/model/get_model.class.php(30): db_mysqli->fetch_next()
#1 /www/wwwroot/www.shzkw.org/caches/caches_template/default/content/yzb_exam_detail.php(153): get_model->fetch_next()
#2 /www/wwwroot/www.shzkw.org/phpcms/modules/yzb/exam.php(291): include('/www/wwwroot/ww...')
#3 /www/wwwroot/www.shzkw.org/phpcms/libs/classes/application.class.php(31): exam->detail()
#4 /www/wwwroot/www.shzkw.org/phpcms/libs/classes/application.class.php(19): application->init()
#5 /www/wwwroot/www.shzkw.org/phpcms/base.php(134): application->__construct()
#6 /www/wwwroot/www.shzkw.org/phpcms/base.php(85): pc_base::_load_class('application', 'libs/classes', 1)
#7 /www/wwwroot/www.shzkw.org/phpcms/base.php(76): pc_base::load_sys_class('application')
#8 /www/wwwroot/www.shzkw.org/index.php(15): pc_base::creat_app()
#9 {main}
thrown in /www/wwwroot/www.shzkw.org/phpcms/libs/classes/db_mysqli.class.php on line 153