20xx年電大工程數(shù)學(xué)(本)期末復(fù)習(xí)輔導(dǎo)小抄參考-wenkub
2023-06-14 18:01:58 本頁面
【正文】 N（3，4）．求：（1）P（5 X 9）,（2）P（X 7）,(已知，)． 7. 設(shè)隨機(jī)變量X ~ N（3，）．求：（1）P（X 5）,（2）P（）,(已知.，,)． 8．設(shè)隨機(jī)變量X ~ N（3，4）．求：（1）P（1 X 7）；（2）使P（X a）= ． (已知，)． 解：（1）P（1 X 7）== == + – 1 = （2）因?yàn)?P（X a）=== 所以 ，a = 3 + = 9．設(shè)，試求：(1)；(2)．（已知）解：(1) (2) 10．從正態(tài)總體N（，4）中抽取容量為625的樣本，計(jì)算樣本均值得= ，求的置信度為99%的置信區(qū)間.(已知 )解：已知，n = 625，且 ~ 因?yàn)?= ， 所以置信度為99%的的置信區(qū)間為： . 11．某車間生產(chǎn)滾珠，已知滾珠直徑服從正態(tài)分布．今從一批產(chǎn)品里隨機(jī)取出9個(gè)，若已知這批滾珠直徑的方差為，．解：由于已知，故選取樣本函數(shù) 已知，經(jīng)計(jì)算得 ，又由已知條件，故此置信區(qū)間為 12. 據(jù)資料分析，某廠生產(chǎn)的一批磚，其抗斷強(qiáng)度，今從這批磚中隨機(jī)抽取9塊，測得抗斷強(qiáng)度（單位：），問這批轉(zhuǎn)的抗斷強(qiáng)度是否合格（）？13. 某一批零件重量，隨機(jī)抽取4個(gè)測量重量（單位：千克），, , ，可否認(rèn)為這批零件的平均重量為15千克（）？14. 某鋼廠生產(chǎn)了一批管材， 每根標(biāo)準(zhǔn)直徑IOOmm ， 今對這批管材進(jìn)行檢驗(yàn)， 隨機(jī)取出9根測得直徑的平均值為9 9 . 9 mm，樣本標(biāo)準(zhǔn)差s == O . 47 ， 已知管材直徑服從正態(tài)分布， 問這批管材的質(zhì)量是否合格? (檢驗(yàn)顯著性水平α == 0 . 05 , tO. 05(8)==2. 306)故接受零假設(shè)，即可以認(rèn)為這批管材的質(zhì)量是合格的.X0123 P求：（1）期望E(X)。t do that it will go on and go on. We have to stop it。s 150th anniversary celebrations and will attend City39。for the racist behaviour of their fans durings actions.CSKA said they were surprised and disappointed by Toure39。t. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).cause there。ll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end.Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him pletely.If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it39。s 21 win.Michel Platini, president of European football39。s about how he felt and I would like to speak to him first to find out what his experience was.Uefa hass celebrations said he wanted to meet Ivory Coast international Toure to discuss his plaint.C
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