【導(dǎo)讀】1．變異：同一性質(zhì)的事物，其個(gè)體觀察值（變量值）之間的差異，在統(tǒng)計(jì)學(xué)上稱為變異。2．統(tǒng)計(jì)推斷：根據(jù)樣本資料的特性對總體的特性作估計(jì)或推論的方法稱統(tǒng)計(jì)推斷，常用方法是參數(shù)估計(jì)和假設(shè)檢驗(yàn)。3．標(biāo)準(zhǔn)差：是方差的算術(shù)平方根，是反映計(jì)量資料全部觀察值離散程度的統(tǒng)計(jì)指標(biāo)，用于描述對稱分布資料，尤其是正態(tài)分布資。表示，樣本標(biāo)準(zhǔn)差用符號(hào)s表示。4．均數(shù)：是算術(shù)均數(shù)的簡稱。習(xí)慣上用μ表示總體均數(shù)，用x表示樣本均數(shù)。均數(shù)反映一組觀察值在數(shù)量上的平均水平，適用于。對稱分布尤其是正態(tài)分布資料。5．動(dòng)態(tài)數(shù)列：動(dòng)態(tài)數(shù)列是一系列按時(shí)間順序排列起來的統(tǒng)計(jì)指標(biāo)，包括絕對數(shù)、相對數(shù)或平均數(shù)，用以說明事物在時(shí)間上的變化。1．計(jì)量資料是指用度量衡的方法測定每個(gè)觀察單位的某項(xiàng)研究指標(biāo)量的大小獲得的連續(xù)型資料，常用的統(tǒng)計(jì)指標(biāo)有平均數(shù)、標(biāo)準(zhǔn)。差，常用的統(tǒng)計(jì)方法有t檢驗(yàn)、u檢驗(yàn)、方差分析、。通常以100為比例基數(shù)，又稱為百分比。

　　

【正文】 dit） 1 （ Ins）插入一行 SHIFT 1 （ STAT） 3 （ Edit） 2 （ DelA）刪除所有 STAT 編輯內(nèi)容 ⑷ STAT 計(jì)算屏幕 在 STAT 編輯屏幕下按 AC 鍵，會(huì)切換到 STAT 計(jì)算屏幕 ⑸使用 STAT 菜單 在在 STAT 編輯屏幕或 STAT 計(jì)算屏幕下，按 SHIFT 1 （ STAT）可顯示 STAT 菜單，顯示內(nèi)容取決于所選的操作類別。 單一變量： 1： Type 2： Data 3： Edit 4： Sum 5： Var 6： MinMax 成對變量： 1： Type 2： Data 3： Edit 4： Sum 5： Var 6： MinMax 7： Reg Type：顯示統(tǒng)計(jì)計(jì)算類別選擇屏幕 Data：顯示 STAT 編輯屏幕 Edit：顯示 Edit 子菜單，編輯 STAT 編輯屏幕內(nèi)容 Sum：顯示計(jì)算總和的求 Sum 子菜單指令 Var：顯示計(jì)算平均值、標(biāo)準(zhǔn)差等的 Var 子菜單指令 MinMax：顯示求得最大值最小值的 MinMax 子菜單指令 Reg：顯示計(jì)算回歸計(jì)算的 Reg 菜單指令 ⑹單一變量 (1VAR)統(tǒng)計(jì)計(jì)算指令 ① Sum 子菜單 SHIFT 1 （ STAT） 4 （ Sum） 1∑ x2 采樣數(shù)據(jù)平方和 2∑ x 采樣數(shù)據(jù)和 ② Var 子菜單 SHIFT 1 （ STAT） 5 （ Var） 1 n 樣本數(shù) 2x 采樣數(shù)據(jù)平均值 3x? n 總體標(biāo)準(zhǔn)差 4x? n1 樣本標(biāo)準(zhǔn)差 ③ MinMax 子菜單 SHIFT 1 （ STAT） 6 （ MinMax） 1MinX 最小值 2MaxX 最大值 ⑺選取線性回歸計(jì)算 (A+BX)時(shí)的指令 ① Sum 子菜單 SHIFT 1 （ STAT） 4 （ Sum） 1∑ x2 x數(shù)據(jù)平方和 2∑ x x采樣數(shù)據(jù)和 3∑ y2 y數(shù)據(jù)平方和 4∑ y y采樣數(shù)據(jù)和 5∑ xy x數(shù)據(jù)與 y數(shù)據(jù)乘積之和 6∑ x3 x數(shù)據(jù)的立方和 ★實(shí)用衛(wèi)生統(tǒng)計(jì)學(xué) ★ 20 7∑ x2y (x數(shù)據(jù)平方乘以 y數(shù)據(jù) )之和 8∑ x4 x數(shù)據(jù) 四次方之 和 ② Var 子菜單 SHIFT 1 （ STAT） 5 （ Var） 1 n 樣本數(shù) 2x x數(shù)據(jù)平均值 3x? n x數(shù)據(jù) 總體標(biāo)準(zhǔn)差 4x? n1 x數(shù)據(jù) 樣本標(biāo)準(zhǔn)差 5y y數(shù)據(jù)平均值 6y? n y總體標(biāo)準(zhǔn)差 7y? n1 y數(shù)據(jù)樣本標(biāo)準(zhǔn)差 ③ MinMax 子菜單 SHIFT 1 （ STAT） 6 （ MinMax） 1MinX x數(shù)據(jù) 最小值 2MaxX x數(shù)據(jù) 最大值 3MinY y數(shù)據(jù)最小值 4MaxY y數(shù)據(jù)最大值 ④ MinMax 子菜單 SHIFT 1 （ STAT） 7 （ Reg） 1A 回歸系數(shù)常數(shù)項(xiàng) A 2B 回歸系數(shù) B 3r 相關(guān)系數(shù) r 4x^ x的估計(jì)值 5y^ y的估計(jì)值 ⑻其他回歸類別 ：略 Visafree policy brings Chengdu biz, tourism boost. Making national headlines several times, Chengdu39。s 72hour visafree policy has attracted wide attention from both Chinese and foreign experts and businessmen since it took effect on Sept 1 last year. The program permits citizens from 51 countries and regions including the United States, Australia, Canada and Japan who have valid visas and flight tickets to a third country to spend three days in the city. The capital of Sichuan province is the first city in the western region of China to offer foreign tourists a threeday visa and the fourth nationwide to adopt the policy following Shanghai, Beijing and Guangzhou. Li Zhiyong, deputy dean of the tourism institute at Sichuan University, said the move contributes to a large increase in the number of overseas tourists and raises the city39。s level of internationalization. The policy will also bring direct economic revenue, Li said. Chengdu has many cultural legacies and is also a paradise for panda lovers with the world39。s largest breeding and research center. Three days are long enough for foreign visitors to visit those iconic tourist spots, he noted. The city is home to the remains of the Jin sha civilization that dates back more than 3,000 years as well as the Qing cheng Mountains and the Du jiang yan irrigation system. Qing cheng has long been recognized as the birthplace of Taoism, 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 convenient. 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。s business development. Rudy Buttignol, president of the public broadcasting pany in British Columbia, ★實(shí)用衛(wèi)生統(tǒng)計(jì)學(xué) ★ 21 Canada, said his work requires frequent travel to Chengdu and the policy makes the trips easier. Data from the city39。s public security bureau 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 2020. 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 ec onomic belt to boost cooperation. The idea has been widely echoed in Central Asian countries, being an en couraging 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 cooperation with Central A