# 2020知到答案 商务统计 最新智慧树满分章节测试答案

## 见面课：常见的假设检验及区间估计（双总体及多总体）

1、问题: One rule that must always be followed in constructing frequency distributions is that __.

B:the midpoint of each class must be a whole number
C:the width of each class is equal to the range
D:the number of intervals must be an odd number

2、问题:

A:are established correctly
B:are not mutually exclusively
C:are not collectively exhaustive
D:don not reference a population parameter

3、问题:When a false null hypothesis is not rejected, the researcher has made a

A: type II error.
B: sampling error.
C:powerful error.
D: type I error

4、问题:

A:
B:
C:
D:

5、问题:Which of the following is an appropriate null hypothesis?

A:
B:
C:
D:

6、问题:In what type of test is the variable of interest the difference between the values of the observations rather than the observations themselves?

A:a test for the equality of variances from 2 independent populations
B:a test for the difference between the means of 2 related populations
C:a test for the difference between the means of 2 independent populations
D:All of the above

7、问题:The test for the equality of two population variances is based on the

A:ratio of the two sample variances
B:difference between the two sample variances
C:difference between the two population variances
D:difference between the sample variances divided by the difference between the sample means

8、问题:

A:zero.
B:-0.5.
C:0.5
D:one.

9、问题:

A:t distribution with 73 degrees of freedom
B: t distribution with 72 degrees of freedom.
C:t distribution with 71 degrees of freedom
D: t distribution with 70 degrees of freedom.

10、问题:

A:
B:
C:
D:

## 见面课：正确理解概率的含义及几种常见的概率统计分布

1、问题:Given the following information:Standard deviation = 8 Coefficient of variation = 64%The mean would then be

A:12.5
B: 8
C:0.64
D:1.25

2、问题:From a population of 500 elements, a sample of 225 elements is selected. It is known that the variance of the population is 900. The standard error of the mean is approximately

A:1.1022
B:2
C:30
D:1.4847

3、问题:A sample of 400 observations will be taken from an infinite population. The population proportion equals 0.8. The probability that the sample proportion will be greater than 0.83 is

A:0.4332
B: 0.9332
C:0.0668
D: 0.5668

4、问题:A weighted average of the value of a random variable, where the probability function provides weights is known as

A:a probability function
B: a random variable
C:the expected value
D:random function

5、问题:The student body of a large university consists of 60% female students. A random sample of 8 students is selected. What is the probability that among the students in the sample exactly two are female?

A:0.0896
B:0.2936
C:0.0413
D:0.0007

6、问题:

A:1.431
B:2.047
C:3.05
D: 21

7、问题:Exhibit 2 The following represents the probability distribution for the daily demand of computers at a local store.

A:0.7
B:0.3
C:0.4
D:1.0

8、问题: If A and B are independent events, then

A: P(A) must be equal to P(B)
B:P(A) must be greater than P(B)
C:P(A) must be less than P(B)
D:P(A) must be equal to P(A│B)

9、问题:The purpose of statistical inference is to provide information about the

A:sample based upon information contained in the population
B:population based upon information contained in the sample
C:population based upon information contained in the population
D:mean of the sample based upon the mean of the population

10、问题:A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is large is known as the

A:approximation theorem
B:normal probability theorem
C:central limit theorem
D:central normality theorem

## 见面课：相关分析及回归分析

1、问题:If two variables, X and Y, have a strong linear relationship, then

A:There may or may not be any causal relationship between X and Y
B:X causes Y to happen
C:Y causes X to happen
D:None of these alternatives is correct

2、问题:In order to test for the significance of a regression model involving 14 independent variables and 255 observations, the numerator and denominator degrees of freedom (respectively) for the critical value of F are

A:14 and 255
B:255 and 14
C:14 and 240
D:13 and 240

3、问题:In a multiple regression analysis model involving 2 independent variables and 15 observations, SSR = 268 and SST = 325. The adjusted coefficient of determination is

A:0.90
B:0.80
C:0.70
D:Not enough information is provided to answer this question

4、问题:Which is considered to be a positive linear relationship

A:x goes up, y goes down
B:x goes down, y goes up
C:x goes down, y goes down
D:x goes up, y goes up
E:both c and d

5、问题:In a regression analysis, if SSE is hypothetically decreased, then

A:R2 will Decrease
B:Se will Increase
C:SST will decrease
D:Both a and b
E:None of the above

## 见面课：置信区间估计和假设检验（单总体）

1、问题:deviation is the distance between a ___ and the ____.v

A:median, mean
B:data point, mean
C: quartile, median
D:data point, median

2、问题:The sum of the deviations may be 0.00. To get around this problem, we use the __ of the deviations

A: square
B:absolute value
C:minimum
D: maximum

3、问题:The reason that we prefer the sample standard deviation as our measure of typical variation instead of the sample variance is that
_

A: the variance is not as accurate a measurement as the standard deviation
B:the standard deviation has been corrected for bias while the variance has not
C:the standard deviation is in the same units as the data values.
D:the variance is in the same units as the data values.

4、问题:The empirical rule tells us that approximately of the values cluster within a distance of 1 standard deviation from the mean for a bell-shaped distribution

A:68%
B:95%
C:99.7%
D:none of the above

5、问题:X is a discrete random variable that can have values from 0 to infinity, and occurrences of the events X counts are independent. The standard deviation of X is equal to the square root of the mean. The probability distribution of X is a(n)
_____distribution.

A: binomial
B:uniform
C:normal
D:Possion

6、问题: When analyzing categorical data, stem and leaf display is an appropriate plot.

A:对
B:错

7、问题: If the population distribution is unknown, in most cases the sampling distribution of the mean can be approximated by the normal distribution if the sample size is at least 15 observations

A:对
B:错

8、问题:Statistical independence means the outcome of one event is independent of the outcome of a second event

A:对
B:错

## 绪论 单元测试

1、 问题:

Penny Bauer, Chief Financial Officer of Harrison Haulage, suspects irregularities in the payroll system, and orders an inspection of ‘each and every payroll voucher issued since 1 January 2005’. Five per cent of the payroll vouchers contained material errors. This is an example of ____.

A:nonparametric statistics
B:nominal data
C:descriptive statistics
D:inferential statistics

## 第一章 单元测试

1、 问题:

Michael Bayley, Marketing Director of UniPower’s Electrical Division, is leading a study to identify and assess the relative importance of product features. Michael directs his staff to design a survey questionnaire for distribution to all of UniPower’s 954 customers. For this study, the set of 954 customers is a ____.

A:

statistic

B:population
C:

parameter

D:

sample

2、 问题:

Claudia Taylor, Director of Global Industrial Sales in Melbourne, is concerned by a deteriorating sales trend. Specifically, the number of customers is stable at 1500 but they are purchasing less each year. She orders her staff to search for causes of the downward trend by selecting a focus group of 40 industrial customers. For this study, the set of 40 industrial customers is a _.

A:statistic
B:sample
C:population
D:parameter

3、 问题:

A politician who is running for the office of premier in a state with 3 million registered voters commissions a survey. In the survey, 53.6% of the 5000 registered voters interviewed say they plan to vote for him. The population of interest is the

A:3 million registered voters in the state.
B:5000 registered voters interviewed.
C:53.6 % of, or 2680, voters interviewed who plan to vote for him
D:46.4% of, or 2320, voters interviewed who plan not to vote for him

4、 问题:

Simon Arnett, Director of Human Resources, is exploring the causes of employee absenteeism at Buderim Bottling during the last operating year (1 January 2005 to 31 December 2005). The average number of absences per employee, calculated from the personnel data of all employees, is a _______.

A:population
B:sample
C:parameter
D:statistic

5、 问题:

A summary measure that is computed from a sample to describe a characteristic of the population is called

A:a parameter
B:a statistic
C:a population
D:Both A and C are correct, since they are the same

6、 问题:

Simon Arnett, Director of Human Resources, is exploring the causes of employee absenteeism at Buderim Bottling during the last operating year (1 January 2005 to 31 December 2005). Personnel records of 50 employees are selected for analysis. (The plant employs 250.) For this study, the average number days absent for these 50 employees is a ____.

A:population
B:sample
C:parameter
D:statistic

7、 问题:

Descriptive statistics deals with methods of

A:organising data.
B:summarising data
C:presenting data in a convenient and informative way
D:doing all of the above

8、 问题:

Which of the following statements is not true?

A:One form of descriptive statistics uses graphical techniques
B:One form of descriptive statistics uses numerical techniques
C:In the language of statistics, the term population refers to a group of people
D:Statistical inference is used to draw conclusions or inferences about characteristics of populations based on sample data

9、 问题:

A student achieves an 82 on the first test in a statistics course. From this, she assumes that her average at the end of the semester (after other tests) will be about 82. This is an example of _______.

A:descriptive statistics
B:inferential statistics
C:nonparametric statistics
D:wishful thinking

10、 问题:

Which of the following is not the goal of descriptive statistics?

A:Summarising data
B:Displaying aspects of the collected data
C:

Reporting numerical findings

D:Estimating characteristics of the population

## 第二章 单元测试

1、 问题:

If data are grouped into intervals and the number of items in each group is listed, this could be called a ___.

A:ogive
B:histogram
C:frequency distribution
D:stem and leaf plot

2、 问题:

If the individual class frequency is divided by the total frequency, the result is the ____.

A:midpoint frequency
B:

cumulative frequency

C:stem and leaf plot
D:relative frequency

3、 问题:

A cumulative frequency polygon is also called ___.

A:an ogive
B:a histogram
C:a frequency polygon
D:a stem and leaf plot

4、 问题:

The number of class intervals in a frequency distribution is usually between _____.

A:3 and 5
B:7 and 9
C:5 and 15
D:1 and 25

5、 问题:

One advantage of a stem and leaf plot over a frequency distribution is that ____.

A:it contains more class intervals
B:the values of the original data are retained
C:

the class midpoints are used as the stem

D:the class midpoints are used as the leaf

6、 问题:

One rule that must always be followed in constructing frequency distributions is that __.

A:the number of classes must be less than 10
B:

each data point can only fall into one class

C:the width of each class is equal to the range
D:the number of intervals must be an odd number

each data point can only fall into one class

7、 问题:

Which of the following is best to show the percentage of a total budget that is spent on each category of items?

A:histogram
B:ogive
C:stem and leaf chart
D:pie chart

8、 问题:

A cumulative frequency distribution would provide _______.

A:a graph of a frequency distribution
B:a running total of the frequencies in the classes
C:the proportion of the total frequencies which fall into each class
D:a very cloudy picture of the frequencies

9、 问题:

The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developed.

 Class Interval Frequency 20-under 40 30 40-under 60 45 60-under 80 80 80-under 100 45

What is the cumulative frequency of the third class?

A:80
B:0.40
C:155
D:75

10、 问题:

The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developed.

 Class Interval Frequency 20-under 40 30 40-under 60 45 60-under 80 80 80-under 100 45

What is the approximate range of the number of phone calls arriving each hour?

A:80
B:200
C:20
D:100

## 第三章 单元测试

1、 问题:

Simon Arnett, Director of Human Resources, is exploring employee absenteeism at the Buderim Bottling during the last operating year. A sample of six personnel records produced the following data: 0, 2, 4, 7, 2, 9. The variance of the number absences per employee is ______.

A:11.6
B:9.67
C:3.41
D:3.11