電大【實用衛(wèi)生統計學】第三次作業(yè)答案參考小抄

1、專業(yè)好文檔實用衛(wèi)生統計學行考冊作業(yè)3答案一、 名詞解釋1、 四格表資料：兩個樣本率的資料又稱為四格表資料，在四格表資料中連個樣本的實際發(fā)生頻數和實際未發(fā)生頻數為基本數據，其他數據可由這四個基本數據推算出來。2、 參數檢驗：是一種要求樣本來自總體分布型是已知的（如正態(tài)分布），在這種假設的基礎上，對總體參數進行統計推斷的假設檢驗。3、 非參數檢驗：是一種不依賴總體分布類型，也不對總體參數進行統計推斷的假設檢驗。4、 直線相關系數：它是說明具有直線關系的兩個變量間，相關關系的密切程度與相關方向的統計指標。相關系數沒有單位，取值范圍是，r的絕對值越大說明兩變量關系越密切5、 完全負相關：這是一種極為特

2、殊的負相關關系，從散點圖上可以看出，有x與y構成的散點完全分布在一條直線上，x增加，y相應減少，算得得相關系數r=-1。二、 填空題：1、 n，p，1-p，np，n（1-p）2、 。3、 任何，嚴重偏態(tài)分布的資料，分布不明。4、 散點圖，直線相關系數5、 直線相關，直線回歸分析三、 選擇題1、a 2、d 3、b 4、b 5、d 6、b 7、c 8、b 9、d 10、b四、簡答題1、答：數學上的函數關系式y=a+bx,是表示變量x與y是嚴格意義上的一一對應關系。每一個x值，都會有一個確定并唯一的y值與之對應，在坐標系中，所有的點（x，y）形成一條直線。而統計中的回歸式，其因變量是y的估計值，它的

3、數值大小與實際的y值是存在一定差距的。從散點圖來看，所有的點(x,y)不是全部落在回歸直線上，而只能是圍繞七均勻的分布。2、答： 直線回歸系數r是說明具有直線關系的兩個變量詞，相關關系的密切程度與相關方向的統計指標。總體相關系數用表示，樣本相關系數用r表示，r是的估計值。相關關系沒有單位，取值范圍是。r值為正，表示兩變量呈正相關，x與y變化趨勢是正向的。r的值為負表示兩變量呈負相關，x與y呈反向變化，通常r的值越大，表示兩變量相關關系越密切。 直線回歸系數b即回歸直線的斜率，b0表示直線從左下方走向右上方，y隨x增大而增大；b0表示直線從左上方走向右下方，y隨x增大而減??；b=0則直線與x軸平

4、行，x與y無直線關系。b的統計學意義是x沒增（減）一個單位，y平均改變b個單位。3、答：（1）四格表檢驗的適用條件1）當且所有時，用檢驗的基本公式或四格表專用公式。2）當但有時，需用四格表檢驗的校正公式。3）若，或時，需用確切概率計算法。（2）配對資料卡方檢驗適用于同一實體對象實驗前后比較、同一樣本用兩種方法檢驗以及配對的兩個受試對象接受兩種不同處理等。當時需用校正公式。(3)行列表資料的卡方檢驗適用條件：不宜有1/5以上格子數的理論頻數小于5，或有1個格子的理論數小于1.4、答：區(qū)別在于：（1）參數檢驗要求樣本來自正態(tài)總體，而非參數檢驗則不對總體分布有任何要求；（2）參數檢驗是對總體參數（如

5、總體均數）進行的檢驗，而非參數檢驗考察的是總體的分布情況。 參數檢驗的優(yōu)點是能充分利用所提供的信息，檢驗效率較高。缺點是對樣本所對應的總體分布有比較嚴格的要求，因此適用資料有限。非參數檢驗的優(yōu)點是不受總體分布類型的限制，適用于任何分布的資料。其缺點是不直接對原始數據作檢驗，從而有可能會損失信息并降低其檢驗效率。5、答：（1）計數資料可進行總體率的參數估計及樣本率（或構成比）比較的假設檢驗（2）計量資料可進行總體均數的參數估計，樣本均數比較的假設檢驗，秩和檢驗，直線相關分析和直線回歸分析等（3）等級資料可進行等級資料秩和檢驗，等級相關檢驗等。6、答：（1）建立檢驗假設差值總體中位數為0差值總體中

6、位數不為0（2）計算統計量t依差值的絕對值從小到大編秩，并按差值的正負分列兩欄。編秩時遇差值為0，則舍去不予編秩，同時在總秩序中要相應減去零的個數。如果遇到絕對值相等的差值時，對符號相同且絕對值相等的差值順序編秩，符號相反且絕對值相等的差值取平均秩次，再在秩次之前帶上原差值的正負號。編完秩次后分別求正負秩次總和，取絕對值最小者為檢驗統計量t。（3）確定p值和做出統計結論（查附表5）五、計算題1、(1)計數資料；是四個表資料；四個基本數據是（2）宜用四格表檢驗方法。適用條件見教材100頁。（3）由于患者未患病新21618舊112132133750由于，所以15,宜用校正公式7.6，v=（2-1）

7、（2-1）=12.140.05尚不能認為兩組工人皮炎患病率有差別。2、（1）完全隨機設計；計量型（2）t檢驗，方差分析要求樣本來自于正態(tài)分布，且兩總體方差相等。 完全隨機設計秩和檢驗對分布無要求。（3）鉛作業(yè)工人（1） 秩次 非鉛作業(yè)（2） 秩次 1.05 12 0.34 3 0.97 11 0.22 1 1.35 16 0.54 5 0.89 9 0.54 6 1.87 20 0.29 2 1.56 19 0.56 7 1.34 15 0.45 4 1.22 14 0.76 8 1.38 17 0.94 10 1.45 18 1.10 13 t1=151 t2=59 ，所以t=59，查表，可

8、得范圍是78132所以p0.05,即兩組工人的血鉛含量不同。3、（1）計量資料；配對設計（2）配對t檢驗差值服從正態(tài)分布配對設計的符號秩和檢驗對分布無要求（3），n=10，查表，得t的范圍是847，t=0不在范圍847內，所以消毒前后沒升水中的細菌總數有差別。winger tuivasa-sheck, who scored two tries in the kiwis 20-18 semi-final win over england, has been passed fit after a lower-leg injury, while slater has been named at fu

9、ll-back but is still recovering from a knee injury aggravated against usa.both sides boast 100% records heading into the encounter but australia have not conceded a try since josh charnleys effort in their first pool match against england on the opening day.aussie winger jarryd hayne is the competit

10、ions top try scorer with nine, closely followed by tuivasa-sheck with eight.but it is recently named rugby league international federation player of the year sonny bill williams who has attracted the most interest in the tournament so far.the kiwi - with a tournament high 17 offloads - has the chanc

11、e of becoming the first player to win the world cup in both rugby league and rugby union after triumphing with the all blacks in 2011.id give every award back in a heartbeat just to get across the line this weekend, said williams.the (lack of) air up there watch mcayman islands-based webb, the head

12、of fifas anti-racism taskforce, is in london for the football associations 150th anniversary celebrations and will attend citys premier league match at chelsea on sunday.i am going to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i w

13、ould like to speak to him first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the racist behaviour of their fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the refe

14、rees actions.cska said they were surprised and disappointed by toures complaint. in a statement the russian side added: we found no racist insults from fans of cska. baumgartner the disappointing news: mission aborted.the supersonic descent could happen as early as sunda.the weather plays an importa

15、nt role in this mission. starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. the balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather

16、lives. it will climb higher than the tip of mount everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbule

17、nce.the balloon will slowly drift to the edge of space at 120,000 feet ( then, i would assume, he will slowly step out onto something resembling an olympic diving platform.they blew it in 2008 when they got caught cold in the final and they will not make the same mistake against the kiwis in manches

18、ter.five years ago they cruised through to the final and so far history has repeated itself here - the last try they conceded was scored by englands josh charnley in the opening game of the tournament.that could be classed as a weakness, a team under-cooked - but i have been impressed by the kangaroos focus in their games since then.they have been concentrating on the sort of stuff that wins you tough, even contests - strong defence, especially on their own goal-line, completing sets and a good kick-chase. theyve been great at all the unglamorous stuff that often goes unnot