绪论 单元测试
1、单选题:
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:nominal data
B:nonparametric statistics
C:descriptive statistics
D:inferential statistics
正确答案:【descriptive statistics】
第一章 单元测试
1、单选题: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:
sample
B:population
C:
parameter
D:
statistic
正确答案:【population
】
2、单选题: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:population
B:sample
C:statistic
D:parameter
正确答案:【sample
】
3、单选题: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
正确答案:【3 million registered voters in the state.
】
4、单选题: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:parameter
B:sample
C:statistic
D:population
正确答案:【parameter
】
5、单选题:A summary measure that is computed from a sample to describe a characteristic of the population is called
A:a statistic
B:a parameter
C:a population
D:Both A and C are correct, since they are the same
正确答案:【a statistic
】
6、单选题: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:statistic
B:parameter
C:sample
D:population
正确答案:【statistic
】
7、单选题:Descriptive statistics deals with methods of
A:presenting data in a convenient and informative way
B:organising data.
C:doing all of the above
D:summarising data
正确答案:【doing all of the above
】
8、单选题:Which of the following statements is not true?
A:One form of descriptive statistics uses graphical techniques
B:In the language of statistics, the term population refers to a group of people
C:One form of descriptive statistics uses numerical techniques
D:Statistical inference is used to draw conclusions or inferences about characteristics of populations based on sample data
正确答案:【In the language of statistics, the term population refers to a group of people
】
9、单选题: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:wishful thinking
B:descriptive statistics
C:inferential statistics
D:nonparametric statistics
正确答案:【inferential statistics
】
10、单选题:Which of the following is not the goal of descriptive statistics?
A:Estimating characteristics of the population
B:Displaying aspects of the collected data
C:Summarising data
D:
Reporting numerical findings
正确答案:【Estimating characteristics of the population
】
第二章 单元测试
1、单选题:If data are grouped into intervals and the number of items in each group is listed, this could be called a _______________.
A:stem and leaf plot
B:ogive
C:frequency distribution
D:histogram
正确答案:【histogram
】
2、单选题:If the individual class frequency is divided by the total frequency, the result is the __________.
A:midpoint frequency
B:relative frequency
C:
cumulative frequency
D:stem and leaf plot
正确答案:【relative frequency
】
3、单选题:A cumulative frequency polygon is also called _______________.
A:a frequency polygon
B:an ogive
C:a histogram
D:a stem and leaf plot
正确答案:【an ogive
】
4、单选题:The number of class intervals in a frequency distribution is usually between ___________.
A:3 and 5
B:5 and 15
C:7 and 9
D:1 and 25
正确答案:【5 and 15
】
5、单选题:One advantage of a stem and leaf plot over a frequency distribution is that __________.
A:
the class midpoints are used as the stem
B:the class midpoints are used as the leaf
C:it contains more class intervals
D:the values of the original data are retained
正确答案:【the values of the original data are retained
】
6、单选题:One rule that must always be followed in constructing frequency distributions is that ________.
A:the width of each class is equal to the range
B:
each data point can only fall into one class
C:the number of classes must be less than 10
D:the number of intervals must be an odd number
正确答案:【
each data point can only fall into one class
】
7、单选题:Which of the following is best to show the percentage of a total budget that is spent on each category of items?
A:ogive
B:histogram
C:pie chart
D:stem and leaf chart
正确答案:【pie chart
】
8、单选题:A cumulative frequency distribution would provide _____________.
A:the proportion of the total frequencies which fall into each class
B:a graph of a frequency distribution
C:a very cloudy picture of the frequencies
D:a running total of the frequencies in the classes
正确答案:【a running total of the frequencies in the classes
】
9、单选题: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:155
B:0.40
C:80
D:75
正确答案:【155
】
10、单选题: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:100
B:80
C:200
D:20
正确答案:【80】
第三章 单元测试
1、单选题: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:3.11
C:3.41
D:9.67
正确答案:【11.6】
2、单选题:Jessica Salas, Managing Director of Salas Products, is reviewing the warranty policy for her company’s new model of car batteries. Life tests performed on a sample of 100 batteries indicated: (1) an average life of 75 months, (2) a standard deviation of 5 months, and (3) battery life is approximately normally distributed. Approximately 68% of the batteries will last between ________________.
A:70 and 80 months
B:60 and 90 months
C:55 and 95 months
D:65 and 85 months
正确答案:【70 and 80 months
】
3、单选题:The average starting salary for graduates at a university is $25,000 with a standard deviation of $2000. A histogram of the data shows the shape to be very erratic so Chebyshev’s Theorem should be used. How many of the graduates would have a starting salary between 21,000 and 29,000?
A:at least 89%
B:at least 68%
C:at least 95%
D:at least 75%
正确答案:【at least 75%
】
4、单选题:The sample standard deviation is found by taking the square root of _______.
A:the coefficient of variation
B:
the sample mean
C:the mean absolute deviation
D:the sample variance
正确答案:【the sample variance
】
5、单选题:The number of standard deviations that a value (X) is above or below the mean is the _______.
A:interquartile range
B:Z score
C:absolute deviation
D:coefficient of variation
正确答案:【Z score
】
6、单选题:In a histogram, the proportion of the total area that must be to the left of the median is()
A:less than 0.50 if the distribution is skewed to the left
B:between 0.25 and 0.60 if the distribution is symmetric and unimodal
C:more than 0.50 if the distribution is skewed to the right
D:exactly 0.50.
正确答案:【exactly 0.50.
】
7、单选题:Which of the following is NOT a measure of central tendency?
A:variance
B:median
C:mean
D:mode
正确答案:【variance
】
8、单选题:Another term for average is ____________.
A:mode
B:median
C:variance
D:mean
正确答案:【mean
】
9、单选题:If the mean of a distribution is greater than the median, then the distribution is ____________.
A:symmetrical about its mean
B:skewed to the left
C:skewed to the right
D:not skewed
正确答案:【skewed to the right
】
10、判断题:The mean is not affected by the extreme values.
A:错
B:对
正确答案:【错】
第四章 单元测试
1、单选题:A process that produces outcomes is called _______.
A:an experiment
B:an event
C:a result
D:population equivalent
正确答案:【an experiment
】
2、单选题:Which of the following is NOT a legitimate probability value?
A:0.23
B:15/16
C:0.67
D:4/3
正确答案:【4/3
】
3、单选题:An outcome of an experiment is called _______.
A:a probability
B:an event
C:a priori elements
D:a complement
正确答案:【an event
】
4、单选题:The list of all elementary events for an experiment is called _______.
A:the sample space
B:the event union
C:the exhaustive list
D:the population space
正确答案:【the sample space
】
5、单选题:If A and B are mutually exclusive events with P(A) = 0.70, then P(B):()
A:cannot be determined from the information given
B:can take any value between 0 and 1
C:can take any value between 0 and 0.70
D:cannot be larger than 0.30
正确答案:【cannot be larger than 0.30
】
6、单选题:If an event is in set X but is not in set Y, which of the following is true?
A:it is in both the union and intersection of X and Y
B:it is in the intersection of X and Y
C:
it is in the union of X and Y
D:it is not in the union of X and Y
正确答案:【
it is in the union of X and Y
】
7、单选题:If the occurrence of one event does not affect the occurrence of another event, then the two events are _______.
A:complements
B:mutually exclusive
C:independent
D:elementary events
正确答案:【independent
】
8、单选题:Let A be the event that a student is enrolled in an accounting course, and let S be the event that a student is enrolled in a statistics course. It is known that 30% of all students are enrolled in an accounting course and 40% of all students are enrolled in statistics. Included in these numbers are 15% who are enrolled in both statistics and accounting. Find P(S).
A:0.15
B:0.30
C:0.55
D:0.40
正确答案:【0.40】
9、单选题:Given P(A) = 0.40, P(B) = 0.50, P(A B) = 0.15. Which of the following is true?
A:A and B are independent
B:A and B are not independent
C:A and B are collectively exhaustive
D:A and B are mutually exclusive
正确答案:【A and B are not independent
】
10、单选题:Meagan Davies manages a portfolio of 200 common stocks. Her staff classified the portfolio stocks by ‘industry sector’ and ‘investment objective’.
Investment | Industry Sector | |||
Objective | Electronics | Airlines | Healthcare | Total |
Growth | 100 | 10 | 40 | 150 |
Income | 20 | 20 | 10 | 50 |
Total | 120 | 30 | 50 | 200 |
Which of the following is NOT true?
A:Growth and Income are complementary events.
B:Electronics and Healthcare are mutually exclusive.
C:Electronics and Growth are dependent.
D:Airlines and Healthcare are collectively exhaustive.
正确答案:【Airlines and Healthcare are collectively exhaustive.
】
第五章 单元测试
1、单选题:Variables which take on values only at certain points over a given interval are called _______.
A:continuous random variables
B:discrete random variables
C:point variables
D:value variables
正确答案:【discrete random variables
】
2、单选题:A variable that can take on values at any point over a given interval is called _______.
A:a value variable
B:a continuous random variable
C:a discrete random variable
D:a point variable
正确答案:【a continuous random variable
】
3、单选题:You are offered an investment opportunity. Its outcomes and probabilities are presented in the following table.
X | P(X) |
–$1000 | .40 |
$0 | .20 |
+$1000 | .40 |
The mean of this distribution is _____________.
A:$200
B:$0
C:–$400
D:$400
正确答案:【$0】
4、单选题:You are offered an investment opportunity. Its outcomes and probabilities are presented in the following table.
X | P(X) |
–$1000 | .40 |
$0 | .20 |
+$1000 | .40 |
The standard deviation of this distribution is _____________.
A:–$400
B:$800,000
C:$894
D:$663
正确答案:【$894
】
5、单选题:The long-run average or mean of a Poisson distribution is usually referred to as _______.
A:m
B:a
C:s
D:l
正确答案:【l
】
6、单选题:The variance of a Poisson distribution is equal to _______.
A:
B:l
C:l/2
D:l2
正确答案:【l
】
7、单选题:If X is a binomial random with n = 8 and p = 0.6, what is the probability that X is less than or equal to 2?
A:0.041
B:0.050
C:0.375
D:0.009
正确答案:【0.050】
8、单选题:If X is a binomial random with n = 8 and p = 0.6, what is the probability that X is greater than 2?
A:0.991
B:0.124
C:0.950
D:0.011
正确答案:【0.950
】
9、单选题:Twenty-five items are sampled. Each of these has the same probability of being defective. The probability that exactly 2 of the 25 are defective could best be found by _______.
A:using the Poisson distribution
B:using the binomial distribution
C:using the exponential distribution
D:using the normal distribution
正确答案:【using the binomial distribution
】
10、单选题:You are offered an investment opportunity. Its outcomes and probabilities are presented in the following table.
X | P(X) |
–$1000 | .40 |
$0 | .20 |
+$1000 | .40 |
Which of the following statements is true?
A:This distribution is symmetric.
B:This distribution is skewed to the left.
C:This distribution is skewed to the right.
D:This is a binomial distribution.
正确答案:【This distribution is symmetric.
】
第六章 单元测试
1、单选题:The normal distribution is an example of _______.
A:a bimodal distribution
B:a continuous distribution
C:an exponential distribution
D:a discrete distribution
正确答案:【a continuous distribution
】
2、单选题:The total area underneath any normal curve is _______.
A:equal to the coefficient of variation
B:equal to the variance
C:equal to 1
D:equal to the mean
正确答案:【equal to 1
】
3、单选题:The area to the left of the mean in any normal distribution is _______.
A:equal to the variance
B:equal to the mean
C:equal to 0.5
D:equal to 1
正确答案:【equal to 0.5
】
4、单选题:For any normal distribution, any value less than the mean would have a _______.
A:negative z-score
B:
negative variance
C:positive z-score
D:negative probability of occurring
正确答案:【negative z-score
】
5、单选题:A standardised normal distribution has the following characteristics:
A:he mean and variance are both equal to 1
B:the mean and variance are both equal to 0
C:the mean is equal to the variance
D:the mean is equal to 0 and the variance is equal to 1
正确答案:【the mean is equal to 0 and the variance is equal to 1
】
6、单选题:If X is a normal random variable with mean 80 and standard deviation 5, calculate the z-score if X = 88.
A:-1.6
B:-1.8
C:1.8
D:1.6
正确答案:【1.6】
7、单选题:Suppose X is a normal random variable with mean 60 and standard deviation 2. A z-score was calculated for a number, and the z-score is 3.4. What is x?
A:66.8
B:53.2
C:56.6
D:63.4
正确答案:【66.8】
8、单选题:Let X be a normal random variable with mean 20 and standard deviation 4. Find P(16 < X < 22).
A:0.4672
B:0.1498
C:0.0328
D:0.5328
正确答案:【0.5328
】
9、单选题:Let X be a normal random variable with mean 20 and standard deviation 4. The 90th percentile of X is ____________.
A:22.698
B:25.126
C:26.579
D:20.000
正确答案:【25.126
】
10、单选题:A z-score is the number of __________ that a value is from the mean.
A:units
B:variances
C:miles
D:standard deviations
正确答案:【standard deviations
】
第七章 单元测试
1、单选题:As a general rule, the normal distribution is used to approximate the sampling distribution of the sample mean only if
A:the underlying population is normal
B:the sample mean is close to 0.50.
C:the sample size n is sufficiently large
D:np and n(1 – p) are both greater than 5
正确答案:【the sample size n is sufficiently large
】
2、单选题:The eight employees of the Art Department and their ‘years of experience’ are listed in the following table.
Employee | A | B | C | D | E | F | G | H |
Experience (years) | 10 | 2 | 1 | 1 | 15 | 7 | 4 | 8 |
If a sample of three employees is selected with replacement, the number of elementary outcomes in the sample space is _______________.
A:64
B:512
C:336
D:56
正确答案:【512
】
3、单选题:A sampling distribution is a distribution of _______________.
A:a sample statistic, such as,
B:excess profits to selected shareholders.
C:a population parameter, such as, µ.
D:a population attribute, such as, employee’s age.
正确答案:【a sample statistic, such as,】
4、单选题:The standard deviation of a sampling distribution is commonly called _______.
A:the uniform spread.
B:the standard error.
C:statistical margin.
D:statistical leverage.
正确答案:【the standard error.
】
5、单选题:The central limit theorem states that if n is large enough, the distribution of the sample means is _____________ distributed regardless of the shape of the population.
A:approximately normally
B:uniformly
C:nonrandomly
D:randomly
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