你要检验两独立样本均数差异是否能推论至总体，而行的t检验
两样本(如某班男生和女生)某变量(如身高)的均数并不相同，但这差别是否能推论至总体，代表总体的情况也是存在著差异呢？
会不会总体中男女生根本没有差别，只不过是你那麼巧抽到这2样本的数值不同？
为此，我们进行t检定，算出一个t检定值。
与统计学家建立的以「总体中没差别」作基础的随机变量t分布进行比较，看看在多少%的机会(亦即显著性sig值)下会得到目前的结果。
若显著性sig值很少，比如<0.05(少於5%机率)，亦即是说，「如果」总体「真的」没有差别，那麼就只有在机会很少(5%)、很罕有的情况下，才会出现目前这样本的情况。虽然还是有5%机会出错(1-0.05=5%)，但我们还是可以「比较有信心」的说：目前样本中这情况(男女生出现差异的情况)不是巧合，是具统计学意义的，「总体中男女生不存差异」的虚无假设应予拒绝，简言之，总体应该存在著差异。
每一种统计方法的检定的内容都不相同，同样是t-检定，可能是上述的检定总体中是否存在差异，也同能是检定总体中的单一值是否等於0或者等於某一个数值。
至於F-检定，方差分析(或译变异数分析，Analysis of Variance)，它的原理大致也是上面说的，但它是透过检视变量的方差而进行的。它主要用于：均数差别的显著性检验、分离各有关因素并估计其对总变异的作用、分析因素间的交互作用、方差齐性(Equality of Variances)检验等情况。
4，T检验和F检验的关系
t检验过程，是对两样本均数(mean)差别的显著性进行检验。惟t检验须知道两个总体的方差(Variances)是否相等；t检验值的计算会因方差是否相等而有所不同。也就是说，t检验须视乎方差齐性(Equality of Variances)结果。所以，SPSS在进行t-test for Equality of Means的同时，也要做Levene's Test for Equality of Variances 。
1.
在Levene's Test for Equality of Variances一栏中F值为2.36, Sig.为.128，表示方差齐性检验「没有显著差异」，即两方差齐(Equal Variances)，故下面t检验的结果表中要看第一排的数据，亦即方差齐的情况下的t检验的结果。
2.
在t-test for Equality of Means中，第一排(Variances=Equal)的情况：t=8.892, df=84, 2-Tail Sig=.000, Mean Difference=22.99
既然Sig=.000，亦即，两样本均数差别有显著性意义！
3.
到底看哪个Levene's Test for Equality of Variances一栏中sig,还是看t-test for Equality of Means中那个Sig. (2-tailed)啊?
答案是：两个都要看。
先看Levene's Test for Equality of Variances，如果方差齐性检验「没有显著差异」，即两方差齐(Equal Variances)，故接著的t检验的结果表中要看第一排的数据，亦即方差齐的情况下的t检验的结果。反之，如果方差齐性检验「有显著差异」，即两方差不齐(Unequal Variances)，故接著的t检验的结果表中要看第二排的数据，亦即方差不齐的情况下的t检验的结果。
4.
你做的是T检验，为什么会有F值呢?
就是因为要评估两个总体的方差(Variances)是否相等，要做Levene's Test for Equality of Variances，要检验方差，故所以就有F值。
另一种解释：
t检验有单样本t检验，配对t检验和两样本t检验。
单样本t检验：是用样本均数代表的未知总体均数和已知总体均数进行比较，来观察此组样本与总体的差异性。
配对t检验：是采用配对设计方法观察以下几种情形，1，两个同质受试对象分别接受两种不同的处理；2,同一受试对象接受两种不同的处理；3，同一受试对象处理前后。
F检验又叫方差齐性检验。在两样本t检验中要用到F检验。
从两研究总体中随机抽取样本，要对这两个样本进行比较的时候，首先要判断两总体方差是否相同，即方差齐性。若两总体方差相等，则直接用t检验，若不等，可采用t'检验或变量变换或秩和检验等方法。
其中要判断两总体方差是否相等，就可以用F检验。
若是单组设计，必须给出一个标准值或总体均值，同时，提供一组定量的观测结果，应用t检验的前提条件就是该组资料必须服从正态分布；若是配对设计，每对数据的差值必须服从正态分布；若是成组设计，个体之间相互独立，两组资料均取自正态分布的总体，并满足方差齐性。之所以需要这些前提条件，是因为必须在这样的前提下所计算出的t统计量才服从t分布，而t检验正是以t分布作为其理论依据的检验方法。
简单来说就是实用T检验是有条件的，其中之一就是要符合方差齐次性，这点需要F检验来验证。
新视野大学英语视听说教程第二版4级答案（全新版本） Unit1 enjoy your feelings
II C B D A D Listening In Task 1 what a clumsy man! Keys: A C D C B Task 2 causes of depression Keys: (1)families (2)chemicals (3)information (4) certain (5)self-esteen (6)thinking patterns (7)mood (8)divorce (9)physical abuse (10)financial difficulties (11)stress (12)anxiety Task 3 happiness index Keys: B D A A C
Let’s Talk Keys: (1) shy (2) crying (3)scared (4) came down (5) fun (6) nice (7) two step (8) argue (9) touch (10) bad time (11) speak (12) comfortable (13) brother (14) adults (15) children (16) secondary (17) growing (18) learn Further Listening and Speaking Task 1: Big John is coming! (S1) owner (S2) running (S3) drop (S4) run (S5) local (S6) yelling, (S7) lives!” (S8) As he’s picking himself up, he sees a large man, almost seven feet tall. (S9) The bartender nervously hands the big man a beer, hands shaking. (S10) “I got to get out of town! Don’t you hear Big John is coming?”Task 2 Reason and emotion Key : A B C C D Task 3 Every cloud has a silver lining Key : T F F T F
Unit 5 test Next Part I Script Directions: Listen to the short dialogs, and then choose the correct answers to the questions. You will hear the recording twice. After the first playing, there will be time for you to choose the correct answers. Use the second playing to check your answers. @ (Listen to the audio recording for the question.) 1. A. The man wants to leave, and the woman tries to keep him. B. The woman wants to leave, and the man tries to keep her. @ C. The woman wants the man to leave, and the man wants to stay. D. The man wants the woman to leave, and the woman wants to stay. 2.(Listen to the audio recording for the question.) , A. The man is employed by a head-hunting company. B. The man works in the same company as the woman. C. The man will take the offer. } D. The man is offering a job to the woman. 3.(Listen to the audio recording for the question.) ] A. Changing her job. B. Transferring to an important position. C. Staying at the company and gather experience. < D. Going back to school to learn more knowledge. 4.(Listen to the audio recording for the question.) ^ A. His new job is very satisfying.
最新版新视野大学英语视听说教程第二版4答案（全新版本）Unit 1 enjoy your feelings! II C B D A D l Listening In Task 1 what a clumsy man! Keys: A C D C B Task 2 causes of depression Keys: (1)families (2)chemicals (3)information (4) certain (5)self-esteen (6)thinking patterns (7)mood (8)divorce (9)physical abuse (10)financial difficulties (11)stress (12)anxiety Task 3 happiness index Keys: B D A A C l Let’s Talk Keys: (1) shy (2) crying (3)scared (4) came down (5) fun (6) nice (7) two step (8) argue (9) touch (10) bad time (11) speak (12) comfortable (13) brother (14) adults (15) children (16) secondary (17) growing (18) learn l Further Listening and Speaking Task 1: Big John is coming!
(S1) owner (S2) running (S3) drop (S4) run (S5) local (S6) yelling, (S7) lives!” (S8) As he’s picking himself up, he sees a large man, almost seven feet tall. (S9) The bartender nervously hands the big man a beer, hands shaking. (S10) “I got to get out of town! Don’t you hear Big John is coming?”Task 2 Reason and emotion Key : A B C C D Task 3 Every cloud has a silver lining Key : T F F T F l Viewing and speaking Key ：(1) seven (2) 150 (3) favorite (4) bridge (5) 111 (6) fast (7) simple (8) trusted (9) stupid (10) did (11) No way (12) ultimate (13) limits (14) skywards (15)&60 (16)cheap Unit tset 1.C D B C D 2. (1)over (2) companionship (3) lover (4) definition (5 scarce (6) diar
大学英语（第二版）听说教程 听力原文 Test 1 Part A Directions: You are going to hear eight short conversations between two speakers. Each will be read only once. After each conversation, a question will be asked about what you have heard. Listen once and choose the right answer to the question you hear. (8 points) 1.M: You like music, don’t you, Sally W: Yes. Classical and light music. But now what you hear everywhere is only noisy music. I can’t stand it. Q: What does the woman mean 2.W: I think I’ll wear my red blouse to the party tonight. M: Why don’t you wear the blue one I think you look in better in it. Q: What does the man mean 3.W: How do you like the pie you’ve had M: Never have I had such a delicious pie. Q: What does the man mean 4.W: Oh, Peter. I’m hungry. I can’t walk any further. M: How about getting something to eat in the restaurant just round the corner by the parking lot Q: Where are the two speakers 5.W: Nice day, isn’t it Want to join us for a swim M: Would you mind waiting for a minute while I get prepared Q: What does the woman mean 6.W: Hi, Tony. Haven’t seen you for some time. How have you been M: I have a car accident last week, but only some minor injuries. Q: What happened to Tony 7.W: Maggie, could you forward this mail to Professor Wang M: Sorry, Phil. My computer has broken down. But I’ll do it as soon as I have it fixed. Q: What does the woman mean 8.W: I’ve been under the weather for quite a few days. I thought my cold was going away. But it seems to get worse now. M: You’ve been complaining too much. Why didn’t you make an appointment with the doctor earlier Q: What does the man mean Part B Directions: You’ll hear two conversations. Each will be read once. Listen carefully and choose the right answers to the questions you hear. (7 points) Conversation 1 Alan: Are you going to the football game today, Betty Betty: No, Alan. But I’ll be watching it on television with some friends. Alan: Weren’t you able to get any tickets Betty: I didn’t try. I really don’t go to games so often. Alan: But don’t you enjoy going Don’t you find it exciting to be part of the crowd Betty: Oh, that’s for sure. Nothing beats the atmosphere at a sporting event: the cheering, all that energy. But sometimes it’s just too inconvenient getting into and out of the
新视野大学英语视听说教程2(第二版)答案(带unit test) Unit1 Listening skills BBDCA Listening in Task1 FTFTF Listening in Task2 BBDAC Listening in Task3 classical，peaceful，relaxing，Jazz，sadness，heavy metal，energy，sporting events，physical labor，road accidents Let's talk Task 1 Good Morning to All，success，musical talents，without，second part，replaced，legal action，real owners Further listening and speaking Task 1
special，joke，talent，proud，loud，joy，honesty，dancer，talk，wondered，capture，fan Task2 BAADC Task 3 TFTTT Unit 1 test 1-5 CCDCB 1.favorite band ， 2.Not anymore ， 3.no longer ， 4.a big fan ， 5.collected ， 6.the ones ， 7.Going crazy ， 8.Maybe to you ， 9.pressure ，10.fall in love ，11.get it ，12.from time to time ，13.Go on ，14.music video 1-5BCDDA 1-5CDABA 6-10 CDCBC Unit2 Listening skills: Making inferences ADBCB Listening in > Task 1
Test 1 Part A Conversation 1: W: Cathy has the habit of keeping us waiting for over 30 minutes. Maybe either you or I should give her a ring before each meeting. M: That's really a nuisance, but I'll do it if you want. Q: What will the man probably do? Conversation 2: M: Could you keep the noise down, Mary? I'm trying to listen to the recording. W: Sorry, it's not me. There is a party downstairs. Q: What does the woman imply? Conversation 3: W: Mr. Brown, I tried to memorize the script but I keep forgetting the lines. M: Look, Jane, you'll be fine if you stop putting so much pressure on yourself. Q: What does the man mean? Conversation 4: M: You've spent too much time doing coursework, Sally. Don't you think you should go out and get some fresh air? W: Thanks for the advice. But this is how I relieve my stress. I'd rather not get too far behind. Q: What can you infer from the woman's response? Conversation 5: M: I'm having trouble making ends meet. It looks like I have to make another phone call to my parents. W: I don't think it would be a problem if you cut down on the discs you buy. Q: What does the woman mean? Conversation 6:
全新版大学英语听说教程答案第一册 Key to Listening CourseBook Book-I（《大学英语》全新版） Unit 1 Part A Communicative Function 1.How are you?/ I'd like you to meet my classmate. 2.I'm.../ May I introduce...to you?/ Pleased to meet you. https://www.doczj.com/doc/a215770672.html,e and meet my family./ ...this is Tom./ It's good to know you./ ...t his is my sister. Part B Text Exercise 1: 1. B 2. D Exercise 2: 1.Yang Weiping: China/ Chemistry/ Likes listening to English programs on radio and TV; enjoys English pop songs/ Started learning English several years ago/ F avorite activity: listening; Difficulty: speaking 2.Virginia: Singapore/ Library science/ To get a good job, one has be to fluent in English./ Started learning English in high school./ Favorite activity: readi ng; Difficulty: writing Part C Exercise: How to Improve Listening Comprehension Among the four skills of listening , speaking, reading and writ ing, I find listening most difficult, because I worry about the wo
Test One 1-5 DDADC 6-10 ACCCB 11-15 DBCBD 16.Researchers 17.murder 18.Fortunately 19.harmony 20.advantage 21.boxers 22.brains 23.Even the most ordinary household items such as irons or can-openers are designed for right-handed people. 24.you can buy anything from left-handed pocket calculators to knives and coffee mugs. 25.People who buy things from the shop say it just makes their everyday life much easier. 26-30 BCDBD 31-35 AABDC Test Two 1-5 CACBD 6-10 CBDCD
11-15 DCDBB 16.course 17.prevent 18.technology 19.benefits 20.particular 21.Due https://www.doczj.com/doc/a215770672.html,munities 23.they are to be seen flying freely in the sky. 24.Recycling should be put into consideration 25.consumers themselves have to be responsible for the proper disposal of their garbage. 26-30 CDAAD 31-35 BDCAB
Unit 1 Listening skills (1)David(2) Leigh(3)Vicky Klein(4) Laura Tish Hill(5)Anthony McDonald Listening in Task 1BDBCA Task 2 John 2,3,5 Lisa 1,4,6 Task 3 1. In order to gain admission to a study course. 2.To corner him. 3.He could answer either ten easy questions or one really difficult. 4.He was jolted / shocked. 5.Because the interviewer had promised that he would only ask one difficult question. Task 4 (1)attention(2)closing(3)five(4)checkouts (5)leave Further listening and speaking Task 1 1. new and different2. on his own 3. a bit confused4. talk with5. sleep in Task 2 FTTFT 第一单元Unit test Part I BDCDB Part II (1)all right (2)better(3)meet(4)how's(5)major(6)What about Part III DBCAC Part IV 1-5 AACBD6-10 DCADB11-15 CBDAD16-20 CBCBD Unit 2 Lead in task 1 baseball basketball kickboxing tennis tai chi jogging skiing swimming Listening skills DACBD
大学英语（第版）听说教程 听力原文 Test 1 Part A Directions: You are going to hear eight short conversations between two speakers. Each will be read only once. After each conversation, a question will be asked about what you have heard. Listen once and choose the right answer to the question you hear. (8 points) 1. M: You like music, don ' t you, Sally W: Yes. Classical and light music. But now what you hear everywhere is only noisy music. I can ' t stand it. Q: What does the woman mean 2. W: I think I 'll wear my red blouse to the party tonight. M: Why don' t you wear the blue one I think you look in better in it. Q: What does the man mean 3. W: How do you like the pie you 've had M: Never have I had such a delicious pie. Q: What does the man mean 4. W: Oh, Peter. I 'm hungry. I can ' t walk any further. M: Howabout getting something to eat in the restaurant just round the corner by the parking lot Q: Where are the two speakers 5. W: Nice day, isn 't it Want to join us for a swim M: Would you mind waiting for a minute while I get prepared Q: What does the woman mean 6. W: Hi, Tony. Haven 't seen you for some time. How have you been M: I have a car accident last week, but only some minor injuries. Q: What happened to Tony 7. W: Maggie, could you forward this mail to Professor Wang M: Sorry, Phil. My computer has broken down. But I ' ll do it as soon as I have it fixed. Q: What does the woman mean
全新版大学英语听说教程3答案 Test 1 Part A 1.b 2.b 3.c 4.d 5.a 6.d 7.c 8.a 9.c 10.c Part B 1) men in any profession 2) lack the necessary training 3) bold enough to take risks 4) male opposition 5) free to enter any career 6) tide is not likely to turn back Part C 1.b 2.d 3.b 4.d 听力原文: Part A Conversation 1: W: Cathy has the habit of keeping us waiting for over 30 minutes. Maybe either you or I should give her a ring before each meeting. M: That's really a nuisance, but I'll do it if you want. Q: What will the man probably do? Conversation 2: M: Could you keep the noise down, Mary? I'm trying to listen to the recording. W: Sorry, it's not me. There is a party downstairs. Q: What does the woman imply? Conversation 3: W: Mr. Brown, I tried to memorize the script but I keep forgetting the lines. M: Look, Jane, you'll be fine if you stop putting so much pressure on yourself. Q: What does the man mean? Conversation 4: M: You've spent too much time doing coursework, Sally. Don't you think you should go out and get some fresh air? W: Thanks for the advice. But this is how I relieve my stress. I'd rather not get too far behind. Q: What can you infer from the woman's response? Conversation 5: M: I'm having trouble making ends meet. It looks like I have to make another phone call to my parents. W: I don't think it would be a problem if you cut down on the discs you buy. Q: What does the woman mean? Conversation 6: W: I hope you enjoyed the movie last night. I wasn't sure I would. M: I wasn't either, but once it started, I simply got glued to the screen.
大学英语听说教程1-4册Test1、2答案 Book 1 Test 1 1-5 ACCBD 6-10 DBDAC 11-15 BDBCD 16-22 language, acquire, success, throughout, radio, concerts, succeed 23 Listening is basically the understanding of words and the relationship between sentences. 24 This is impossible even when we listen in our own language. 25 he can find out his strengths and weaknesses 26-30 CDCCD 31-35 DBDCDC Test 2 1-5 CBCDA 6-10 DCAAB 11-15 DBDBD 16-22 value, fashionable, delicious, possessing, source, sake, means 23 profiting at the expense of their victims 24 But in my opinion the truly happy are those who make money through their work and live within their income. 25 in itself it has little value if it does not give people real happiness 26-30 BCCDC 31-35 CDBDC Book 2 Test 1 1-5 BCBCB 6-10 CABDB 11-15 DCCBD 16-22 stocks, exhibition, techniques, activities, research, modern, software 23 Delivery time for e-mail from Europe to the USA is about 10 seconds 24 What’s really extraordinary about the internet is the amount and variety of information available. 25 Services are also available that allow you to do your banking, reserve airline tickets, and even shop for a Mother’s Day gift. 26-30 CDCCC 31-35 ADBCA Test 2 1-5 DCDCD 6-10 BCADD 11-15 ABCBC 16-22 forecast, unusual, Fortunately, extreme, rarely, global, rush 23 People enjoy discussing the snow, complaining about the cold 24 Contrary to popular opinion, it does not rain all the time 25 Thanks to the rain, Britain has a rich countryside, which is famous for its deep green color,
新视野大学英语第二版视听说教程4答案 Unit1 Basic listening practice C B D A D Listening in > Task 1 A C D C B Listening in > Task 2 1.families 2.chemicals https://www.doczj.com/doc/a215770672.html,rmation 4.certain 5.self-esteen 6.thinking partterns 7.mood 8.divorce 9.physical abuse 10.financial difficulties 11.stress 12.anxiety Listening in > Task 3 B D A A C Let's talk > Task 1 1.shy 2.crying 3.scared 4.came down 5.fun 6.nice 7.two step 8.argue 9.touch 10.bad time 11.speak https://www.doczj.com/doc/a215770672.html,fortable 13.brother 14.adults 15.children 16.secondary 17.growing 18.learn Further listening and speaking > Further listening > Task 1 1.owner 2.running 3.drop 4.run 5.local 6.yelling 7.lives 8.As he’s picking himself up, he sees a large man, almost seven feet tall. 9.The bartender nervously hands the big man a beer, hands shaking. 10.”I got to get out of town! Don’t you hear Big John is coming Task 2 A B C C D Task 3 A B B A B Further listening and speaking > Viewing and speaking > Task 1 1.seven 2.150 3.favorite 4.bridge 5.111 6.fast 7.simple 8.trusted 9.stupid 10.did 11.No way 12.ultimate 13.limits 14.skywards 15.$60 16.cheap Unit test Part I C D B C D Part II 1. over 2. companionship 3. lover 4.definition. 5. scarce 6. diary 7. sight 8. Thank God, I've done my duty 9. In a workforce made up entirely of happy people, the competitive edge would soon be lost 10.It may take centuries before philosophers and scientists can arrive at a clear definition of happiness B A D C C A D C A B C D B A A Unit2 Lead in > Task 1 f d a e h I b c j B A C D B Listening in > Task 1 C A A D B Task 2
全新版大学英语（第二版）听说教程3 Test1 & Test2答案 Test One 1-5 DDADC 6-10 ACCCB 11-15 DBCBD 16. Researchers 17. Murder 18. Fortunately 19. harmony 20. advantage 21. Boxers 22. brains 23. Even the most ordinary household items such as irons or can-openers are designed for right-handed people. 24. you can buy anything from left-handed pocket calculators to knives and coffee mugs. 25. People who buy things from the shop say it just makes their everyday life much easier. 26-30 BCDBD 31-35 AABDC Test Two 1-5 CACBD 6-10 CBDCC 11-15 DCDBB 16. course 17. prevent 18. technology 19. benefits 20.Particular 21. Due 22. Communities 23. they are to be seen flying freely in the sky. 24.Recycling should be put into consideration
全新版大学英语听说教程 t e s t听力原文 This manuscript was revised by the office on December 10, 2020.
大学英语（第二版）听说教程 听力原文 Test 1 Part A Directions: You are going to hear eight short conversations between two speakers. Each will be read only once. After each conversation, a question will be asked about what you have heard. Listen once and choose the right answer to the question you hear. (8 points) 1.M: You like music, don’t you, Sally W: Yes. Classical and light music. But now what you hear everywhere is only noisy music. I can’t stand it. Q: What does the woman mean 2.W: I think I’ll wear my red blouse to the party tonight. M: Why don’t you wear the blue one I think you look in better in it. Q: What does the man mean 3.W: How do you like the pie you’ve had M: Never have I had such a delicious pie. Q: What does the man mean 4.W: Oh, Peter. I’m hungry. I can’t walk any further. M: How about getting something to eat in the restaurant just round the corner by the parking lot Q: Where are the two speakers 5.W: Nice day, isn’t it Want to join us for a swim M: Would you mind waiting for a minute while I get prepared Q: What does the woman mean 6.W: Hi, Tony. Haven’t seen you for some time. How have you been M: I have a car accident last week, but only some minor injuries. Q: What happened to Tony 7.W: Maggie, could you forward this mail to Professor Wang M: Sorry, Phil. My computer has broken down. But I’ll do it as soon as I have it fixed. Q: What does the woman mean 8.W: I’ve been under the weather for quite a few days. I thought my cold was going away. But it seems to get worse now. M: You’ve been complaining too much. Why didn’t you make an appointment with the doctor earlier Q: What does the man mean Part B Directions: You’ll hear two conversations. Each will be read once. Listen carefully and choose the right answers to the questions you hear. (7 points)