问题
选择题
设随机变量ξ服从标准正态分布N(0,1),在某项测量中,已知P(|ξ|<1.96)=0.950,则ξ在(-∞,-1.96)内取值的概率为( ) |
A.0.025 B.0.050 C.0.950 D.0.975 |
答案
答案:A
设随机变量ξ服从标准正态分布N(0,1),在某项测量中,已知P(|ξ|<1.96)=0.950,则ξ在(-∞,-1.96)内取值的概率为( ) |
A.0.025 B.0.050 C.0.950 D.0.975 |
答案:A
选择适当的选项填入短文中的横线上,期中有两个多余的选项。 | |
Thank you very much l. _____ your letter. Beijing 2. _____beautiful! I like. Beijing 3. _____ I like China. Now I'm fine and I'm busy 4. _____my lessons. I have seven classes every day. There are 5. _____ in the morning and three in the afternoon. I have seven subjects this term. I like music. science and history. My 6. _____ subject is biology. because it is very interesting. Yes. my English is very 7. _____. and I like it, but I 8. _____ like math. because it is difficult for 9. _____, and I can't learn it well. I can play tennis and J often play it with my friends after school. Do you play tennis? Can you 10. _____ Chinese? Please write to me soon. Love, Jerry |