最新電大應(yīng)用概率統(tǒng)計(jì)試題考試小抄(存儲(chǔ)版)
【正文】 ? ? ? ? ? ? ?； C．002211? ? ? ?[ ( 2 ) , ( 2 ) ]y t n y t nnn????? ? ? ? ? ?； D．002211? ? ? ?[ , ]yynn??? ? ? ?? ? ? ?． 6．樣本容量為 n 時(shí)，樣本方差 2S 是總體方差 2? 的無(wú)偏估計(jì)量，這是因?yàn)椋? ）． A． ? ?22ES ?? ； B． ? ? 22ES n?? ； C． 22S ?? ； D． 22S ?? ． 三、解下列各題（ 6 小題，共 48 分） 12 1．設(shè)總體 ? ?~ 0,1XN ， 12, , , nX X X 為簡(jiǎn)單隨機(jī)樣本，且3 2124( 1)3 iiniiXnFX??????．證明：~ (3, 3)F F n? ． （ 6 分） 2．已知連續(xù)型隨機(jī)變量 X 的分布函數(shù)為 0 , 1 。s public security bure au shows some 100 foreign visitors enjoyed the 72hour policy by the end of March, most of them from the United States, the United Kingdom and Germany. Chengdu also reported robust growth in its overall tourist industry last year. Official statistics show that it received some 150 million tourists last year, an increase of 28 percent from 2021. Around million came from abroad, an increase of 12 percent. Total revenue from tourism surpassed 133 billion yuan ($). During his visit to Kazakhstan in September, Chinese President Xi Jinping proposed that China and Central Asia join hands to build a Silk Road economic belt to boost cooperation. The idea has been widely echoed in Central Asian countries, being an encouraging blueprint for Chinese areas along the Silk Road that has linked Asia and Europe for more than 2,000 years. In the next three weeks, China Daily reporters will travel through the belt in China and in Kazakhstan, Uzbekistan and Turkey. They will show the progress and expectations of the countries, businesses and peoples on the route. Shaanxi the start of the ancient Silk Road has positioned itself as the new starting point for the development of the Silk Road Economic Belt, which will strengthen China39。s ancient indigenous religion, while Du jiang yan is considered to be the oldest functioning watercontrol project in the world. Chengdu ranked third in tourist facilities, management and services among 60 Chinese cities in a customer satisfaction survey released last year. But, Li added that efforts are still needed to develop more tourism products, improve English services and provide accurate translation of traffic signs and scenic billboards. Zhao Yun, chairwoman of British Chamber of Commerce Southwest China, told China Daily that his colleagues found the policy very co nvenient. A British client once flew here and stayed for just one day to check her ordered goods, she said. Zhao was born in Shanxi province, but she has lived in Chengdu for more than 10 years. My life was like a running race moving from place to place. I also lived in Beijing and Shanghai before, she said. But Chengdu is a place that you never want to leave once settling down. It is now my second hometown, she said. If the environment is further improved, the city will attract more people to visit and live, with the 72hour visafree policy and pelling conditions in transportation, culture, climate and cuisine, he said. Foreigners also gave positive feedback on the policy. A spokesman from Dell Inc said the pany has a global hub of operation in Chengdu, so the threeday visa has an immediate and positive influence on the pany39。 二、單項(xiàng)選擇題（每小題 3 分，本題共 18 分） 1．從數(shù)字 1， 2， 3， 4， 5 中，隨機(jī)抽取 3 個(gè)數(shù)字（允許重復(fù)）組成一個(gè)三位數(shù)， 其各位數(shù)字之和等于 9 的概率為（ ）． 11 A．12513； B．12516； C．12518； D．12519． 2． 如果隨機(jī)變量 X 的密度函數(shù)為 , 0 1。 （ ） 用 MINITAB 軟件 求回歸方程， 在菜單中選擇 如下命令即可得 ： ......St at ANOV A Balanc e d ANOV A?? 四、計(jì)算題（每小題 8 分，共 8?7=56 分） 某連鎖總店屬下有 10 家分店，每天每家分店訂貨的概率為 p，且每家分 店的訂貨行為是相互獨(dú)立的，求 （ 1） 每天訂貨分店的家數(shù) X 的分布律； （ 2） 某天至少有一家分店訂貨的概率。 設(shè)二維離散型隨機(jī)變量 X、 Y 的聯(lián)合分布律為： 則 a, b 滿足條件： ___________________。 （ ） 如果 X、 Y 是兩個(gè)相互獨(dú)立的隨機(jī)變量，則 ? ? ? ? ? ?D X Y D X D Y? ? ? （ ） 若兩隨機(jī)變量具有雙曲線類型的回歸關(guān)系，則可作適當(dāng)?shù)淖兞看鷵Q轉(zhuǎn)化為 線性回歸關(guān)系。3
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