1、 The most frequent data, or data corresponding to the highest frequency. Mode is not affected by extreme values. There may not be a mode. There may be several modes. Used for either numerical or categorical data.8、 Median is the value that splits a ranked set of data into two equal parts. Median is
2、not affected by extremely large or small values and is therefore a valuable measure of central tendency when such values occur.9、 Standard Deviation: A measure of the variation of data from the mean. The most commonly used measure of variation. Represented by the symbol s. Shows how the data is dist
3、ributed around the mean.10、 Probability is the chance of an occurrence of an event. Probability of an event always lies between 0 and 1. The sum of the probabilities of every possible outcome or event is 1. The probability of the complement A is given by 1-P(A).11、 Properties of Normal distribution:
4、Continuous random variable. Bell-shaped & symmetrical. Mean, median, mode are equal Area under the curve is 1.12、 The Central Limited Theorem:If the population followed normal distribution, the sampling distribution of mean is followed normal distribution. If the population do not followed normal di
5、stribution, but the sample size is larger than 30, the sampling distribution of mean is followed normal distribution.Part2选择题Topic 1 - Introduction to Business Statistics & Data CollectionQ1. The universe or totality of items or things under consideration is called:a. a sample. b. a population. c. a
6、 parameter. d. none of the above. Q2. Those methods involving the collection, presentation, and characterization of a set of data in order to properly describe the various features of that set of data are called:a. inferential statistics. b. total quality management. c. sampling. d. descriptive stat
7、istics. Q3. The portion of the universe that has been selected for analysis is called:b. a frame. d. a statistic. Q4. A summary measure that is computed to describe a numerical characteristic from only a sample of the population is called:a. a parameter. b. a census. c. a statistic. d. the scientifi
8、c method. Q5. A summary measure that is computed to describe a characteristic of an entire population is called:d. total quality management. Q6. The process of using sample statistics to draw conclusions about population parameters is called:b. experimentation. c. primary sources. Q7. Which of the f
9、our methods of data collection is involved when a person retrieves data from an online database?a. published sources. c. surveying. d. observation. Q8. Which of the four methods of data collection is involved when people are asked to complete a questionnaire?Q9. Which of the four methods of data col
10、lection is involved when a person records the use of the Los Angeles freeway system?Q10. A focus group is an example of which of the four methods of data collection?Q11. Which of the following is true about response rates?a. The longer the questionnaire, the lower the rate. b. Mail surveys usually p
11、roduce lower response rates than personal interviews or telephone surveys. c. Question wording can affect a response rate. d. d. All of the above. Q12. Which of the following is a reason that a manager needs to know about statistics?a. To know how to properly present and describe information. b. To
12、know how to draw conclusions about the population based on sample information. c. To know how to improve processes. d. All of the above. Scenario 1-1Questions 13-15 refer to this scenario:An insurance company evaluates many variables about a person before deciding on an appropriate rate for automobi
13、le insurance. Some of these variables can be classified as categorical, discrete and numerical, or continuous and numerical. Q13. Referring to Scenario 1-1 (above), the number of claims a person has made in the last three years is what type of variable?a. Categorical. b. Discrete and numerical. c. C
14、ontinuous and numerical. d. None of the above. Q14. Referring to Scenario 1-1 (above), a persons age is what type of variable?Q15. Referring to Scenario 1-1 (above), a persons gender is what type of variable?Q16. Which of the following can be reduced by proper interviewer training?a. Sampling error.
15、 b. Measurement error. c. Coverage error. d. Nonresponse error. Scenario 1-2Questions 17-19 refer to this scenario:Mediterranean fruit flies were discovered in California a few years ago and badly damaged the oranges grown in that state. Suppose the manager of a large farm wanted to study the impact
16、 of the fruit flies on the orange crops on a daily basis over a 6-week period. On each day a random sample of orange trees was selected from within a random sample of acres. The daily average number of damaged oranges per tree and the proportion of trees having damaged oranges were calculated. Q17.
17、Referring to Scenario 1-2 (above), the two main measures calculated each day (i.e., average number of damaged oranges per tree and proportion of trees having damaged oranges) are called _.a. statistics. b. parameters. c. samples. d. populations. Q18. Referring to Scenario 1-2 (above), the two main m
18、easures calculated each day (i.e., average number of damaged oranges per tree and proportion of trees having damaged oranges) may be used on a daily basis to estimate the respective true population _.a. estimates. c. statistics. d. frame. Q19. Referring to Scenario 1-2 (above), in this study, drawin
19、g conclusions on any one day about the true population characteristics based on information obtained from the sample is called _.a. evaluation. b. descriptive statistics. c. inferential statistics. d. survey. Scenario 1-3Questions 20 and 21 refer to this scenario:The Quality Assurance Department of
20、a large urban hospital is attempting to monitor and evaluate patient satisfaction with hospital services. Prior to discharge, a random sample of patients is asked to fill out a questionnaire to rate such services as medical care, nursing, therapy, laboratory, food, and cleaning. The Quality Assuranc
21、e Department prepares weekly reports that are presented at the Board of Directors meetings and extraordinary/atypical ratings are easy to flag.Q20. Referring to Scenario 1-3 (above), true population characteristics estimated from the sample results each week are called _.a. inferences. c. estimates.
22、 d. data. Q21. Referring to Scenario 1-3 (above), a listing of all hospitalised patients in this institution over a particular week would constitute the _.a. sample. b. population. d. parameters. Scenario 1-4Questions 22-24 refer to this scenario:The following are the questions given to Sheila Druck
23、er-Ferris in her college alumni association survey. Each variable can be classified as categorical or numerical, discrete or continuous.Q22. Referring to Scenario 1-4 (above), the data for the number of years since graduation is categorised as: _.a. numerical discrete. b. categorical. c. numerical c
24、ontinuous. Q23. Referring to Scenario 1-4 (above), the data for the number of science majors is categorised as: _.a. categorical. b. numerical continuous. c. numerical discrete. Q24. Referring to Scenario 1-4 (above), the data for tabulating the level of job satisfaction (High, Moderate, Low) is cat
25、egorised as: _.a. numerical continuous. Topic 2: Organising and Presenting dataQ1 The width of each bar in a histogram corresponds to the:a. boundaries of the classes. b. number of observations in the classes. c. midpoint of the classes. d. percentage of observations in the classes. Q2 When construc
26、ting charts, which of the following chart types is plotted at the class midpoints?a. Frequency histograms. b. Percentage polygons. c. Cumulative relative frequency ogives. d. Relative frequency histograms. Q3 When polygons or histograms are constructed, which axis must show the true zero or origin?a. The horizontal axis. b. The vertical axis. c. Both the horizontal and vertical axes. d. Neither the
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