【文章內(nèi)容簡(jiǎn)介】 (1)函數(shù)關(guān)系中的自變量與因變量由于觀察或?qū)嶒?yàn)出現(xiàn)誤差，其關(guān)系值也不可能絕對(duì)固定，有時(shí)也通過(guò)相關(guān)關(guān)系來(lái)反映。 (2)相關(guān)關(guān)系的定量分析必須用函數(shù)表達(dá)式來(lái)近似地反映自變量與因變量之間的一般關(guān)系值。 ？ 答：隨機(jī)抽樣調(diào)查是從研究對(duì)象的總體中，按照隨機(jī)原則抽取一部分單位作為樣本進(jìn)行調(diào)查，并用調(diào)查結(jié)果推斷總體。它具有以下特點(diǎn)：（ 1）抽取樣本的客觀性。（ 2）可以比較準(zhǔn)確地推斷總體。（ 3）是一種比較節(jié)省的調(diào)查方法 。（ 4）應(yīng)用范圍廣泛，特別適用于研究 市場(chǎng)現(xiàn)象的數(shù)量表現(xiàn)。 。 答：（ 1）根據(jù)預(yù)測(cè)目的，選擇和確定自變量和因變量。（ 2）確定回歸方程，建立預(yù)測(cè)模型。（ 3）對(duì)回歸模型進(jìn)行檢驗(yàn)，測(cè)定預(yù)測(cè)誤差。（ 4）用預(yù)測(cè)模型計(jì)算預(yù)測(cè)值，并對(duì)預(yù)測(cè)值作區(qū)間估計(jì)。 四、計(jì)算題 1．某市常住居民 55 萬(wàn)戶，抽選 100 戶進(jìn)行食糖需求量調(diào)查，得知樣本平均每戶年需求量為 12 公斤，樣本標(biāo)準(zhǔn)差為 4。根據(jù)上述資料，要求： (1)用單純隨機(jī)抽樣方式的重復(fù)抽樣公式，計(jì)算抽樣誤差。 (2)若置信度為 95%，試估計(jì)樣本置信區(qū)間，并推斷全市食糖需求量的置信區(qū)間。 2．某地區(qū) 2021～ 2021年水稻產(chǎn)量資料如下表： 試用最小平方法預(yù)測(cè) 2021 年水稻產(chǎn)量。（按直線趨勢(shì)法計(jì)算 ） 解：設(shè)直線方程為 Y=a+bt 列參數(shù)計(jì)算表為： 3．某市常住居民 70 萬(wàn)人，抽選 1400人進(jìn)行調(diào)查，得知人均年食糖需要量為 ，樣本方差為 ，根據(jù)上述資料，要求： (1)用單純隨機(jī)抽樣方式的重復(fù)抽樣公式，計(jì)算抽樣誤差。 (2)若置信度為 95％，試估計(jì)樣本年人均食糖需求量置信區(qū)間，并 推斷全市食糖需求量置信區(qū)間。 4．某商場(chǎng)銷售額歷史資料如下： (單位：億元 ) 年 份 01 02 03 04 05 銷售額 試用最小平方法擬合直線方程，預(yù)測(cè)該商場(chǎng) 2021 年銷售額。 5．某市常住居民 16 萬(wàn)戶，抽選 8000戶進(jìn)行洗衣機(jī)普及率調(diào)查，得知樣本平均每百戶洗衣機(jī)保有量為 60 臺(tái)。根據(jù)上述資料，要求： （ 1）用單純隨機(jī)抽樣方式的重復(fù)抽樣公式，計(jì)算抽樣誤差。 （ 2）若 置信度為 95％，試估計(jì)樣本置信區(qū)間，并推斷全市洗衣機(jī)保有量置信區(qū)間。 解：因?yàn)?n=8000 p=60% μ= 即 μ=% 又因?yàn)橹眯哦葹?95% 所以 t= Δ=tμ=% 所以樣本置信區(qū)間為： 60%177。% 即 %～ % 又因?yàn)?N=16 萬(wàn)，所以該市居民年洗衣機(jī)保有量置信區(qū)間為： %16 ～ %16 即 94272～ 97728（臺(tái)） 6．某商場(chǎng)銷售額歷史資料如下：（單位：百萬(wàn)元） 年份 03 04 05 06 07 銷 售額 560 620 685 747 808 試用最小平方法擬合直線方程，預(yù)測(cè)該商場(chǎng) 2021 年銷售額。（要求列出參數(shù)計(jì)算表） 解：設(shè)直線方程為： Y=a+bt 列參數(shù)計(jì)算表為： 年份 ti yi tiyi ti2 03 2 560 1120 4 04 1 620 620 1 05 0 685 0 0 06 1 747 747 1 07 2 808 1616 4 Σ 0 3420 632 10 所以， a=684 b= 所以 Y=684+ 令 t=3 Y=684+3=( 百萬(wàn)元 ) 7. 某縣有居民家庭 40000 戶，抽選 1600戶進(jìn)行食糖需求量抽樣調(diào)查。調(diào)查結(jié)果，樣本平均每戶需要食糖 4 公斤，樣本標(biāo)準(zhǔn)差為 8。根據(jù)上述資料，要求： （ 1）用單純隨機(jī)重復(fù)抽樣的誤差計(jì)算公式，計(jì)算出抽樣誤差。 a=8 n=1600 181。x （ 2）設(shè)要求置信度為 95%，試估計(jì)該樣本戶平均食糖需求量置信區(qū)間。 因?yàn)橹眯哦葹?95%，所以 t= △ x =t181。x == 置信區(qū)間為： ～ 4+ 即 ～ （ 3）以樣本指標(biāo)推斷該市居民全年食糖需求量的置信區(qū)間。 40000*～ 40000* 即： 144320～ 175680 （ 4）已知食糖銷售量的季節(jié)指數(shù)，第一季度為 108%，按上述食糖年人均需要量置信區(qū)間，估算出該市第一季度食糖需求量的置信區(qū)間。 (144320/4)*～ (175680/4)* ～ 請(qǐng)您刪除一下內(nèi)容， O(∩ _∩ )O 謝謝?。?！ 2021年中央電大期末復(fù)習(xí)考試小抄大全，電大期末考試必備小抄，電大考試必過(guò)小抄 Basketball can make a true claim to being the only major sport that is an American invention. From high school to the professional level, basketball attracts a large following for live games as well as television coverage of events like the National Collegiate Athletic Association (NCAA) annual tournament and the National Basketball Association (NBA) and Women39。s National Basketball Association (WNBA) playoffs. And it has also made American heroes out of its player and coach legends like Michael Jordan, Larry Bird, Earvin Magic Johnson, Sheryl Swoopes, and other great players. At the heart of the game is the playing space and the equipment. The space is a rectangular, indoor court. The principal pieces of equipment are the two elevated baskets, one at each end (in the long direction) of the court, and the basketball itself. The ball is spherical in shape and is inflated. Basketballs range in size from in (7276 cm) in circumference, and in weight from 1822 oz (510624 g). For players below the high school level, a smaller ball is used, but the ball in men39。s games measures in (7576 cm) in circumference, and a women39。s ball is in (7274 cm) in circumference. The covering of the ball is leather, rubber, position, or synthetic, although leather covers only are dictated by rules for college play, unless the teams agree otherwise. Orange is the regulation color. At all levels of play, the home team provides the ball. Inflation of the ball is based on the height of the ball39。s bounce. Inside the covering or casing, a rubber bladder holds air. The ball must be inflated to a pressure sufficient to make it rebound to a height (measured to the top of the ball) of 4954 in ( m) when it is dropped on a solid wooden floor from a starting height of 6 ft ( m) measured from the bottom of the ball. The factory must test the balls, and the air pressure that makes the ball legal in keeping with the bounce test is stamped on the ball. During the intensity of high school and college tourneys and the professional playoffs, this inflated sphere mands considerable attention. Basketball is one of few sports with a known date of birth. On December 1, 1891, in Springfield, Massachusetts, James Naismith hung two halfbushel peach baskets at the opposite ends of a gymnasium and outlined 13 rules based on five principles to his students at the International Training School of the Young Men39。s Christian Association (YMCA), which later became Springfield College. Naismith (18611939) was a physical education teacher who was seeking a team sport with limited physical contact but a lot of running, jumping, shooting, and the handeye coordination required in handling a ball. The peach baskets he hung as goals gave the sport the name of basketball. His students were excited about the game, and Christmas vacation gave them the chance to tell their friends and people at their local YMCAs about the game. The association leaders wrote to Naismith asking for copies of the rules, and they were published in the Triangle, the school newspaper, on January 15,1892. Naismith39。s five basic principles center on the ball, which was described as large, light, and handled with the hands. Players could not move the ball by running alone, and none of the players was restricted against handling the ball. The playing area was also open to all players, but there was to be no physical contact between players。 the ball was the objective. To score, the ball had to be shot through a horizontal, elevated goal. The team with the most points at the end of an allotted time period wins. Early in the history of basketball, the local YMCAs provided the gymnasiums, and membership in the anization grew rapidly. The size of the