大学MOOC 数理统计学(云南大学)1454637171 最新慕课完整章节测试答案
第一章简介及数据收集
文章目录
第一章测验题
1、单选题：
The process of using sample statistics to draw conclusions about true population parameters is called
选项：
A: statistical inference.
B: the scientific method.
C: sampling.
D: descriptive statistics.
答案: 【 statistical inference.】
2、单选题：
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
选项：
A: statistical inference.
B: the scientific method.
C: sampling.
D: descriptive statistics.
答案: 【 descriptive statistics.】
3、单选题：
The collection and summarization of the socioeconomic and physical characteristics of the employees of a particular firm is an example of
选项：
A: inferential statistics.
B: descriptive statistics.
C: a parameter.
D: a statistic.
答案: 【 descriptive statistics.】
4、单选题：
The estimation of the population average family expenditure on food based on the sample average expenditure of 1,000 families is an example of
选项：
A: inferential statistics.
B: descriptive statistics.
C: a parameter.
D: a statistic.
答案: 【 inferential statistics.】
5、单选题：
The universe or "totality of items or things" under consideration is called
选项：
A: a sample.
B: a population.
C: a parameter.
D: a statistic.
答案: 【 a population.】
6、单选题：
The portion of the universe that has been selected for analysis is called
选项：
A: a sample.
B: a frame.
C: a parameter.
D: a statistic.
答案: 【 a sample.】
7、单选题：
A summary measure that is computed to describe a characteristic from only a sample of the population is called
选项：
A: a parameter.
B: a census.
C: a statistic.
D: the scientific method.
答案: 【 a statistic.】
8、单选题：
A summary measure that is computed to describe a characteristic of an entire population is called
选项：
A: a parameter.
B: a census.
C: a statistic.
D: the scientific method.
答案: 【 a parameter.】
9、单选题：
Which of the following is most likely a population as opposed to a sample?
选项：
A: respondents to a newspaper survey.
B: the first 5 students completing an assignment.
C: every third person to arrive at the bank.
D: registered voters in a county.
答案: 【 registered voters in a county.】
第二章用图表展示数据
第二章测验题
1、单选题：
An insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for automobile insurance. A representative from a local insurance agency selected a random sample of insured drivers and recorded, X, the number of claims each made in the last 3 years, with the following results. f is the corresponding frequency.X 1 2 3 4 5 f 14 18 12 5 1How many total claims are represented in the sample?
选项：
A: 15
B: 50
C: 111
D: 250
答案: 【 111】
2、单选题：
An insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for automobile insurance. A representative from a local insurance agency selected a random sample of insured drivers and recorded, X, the number of claims each made in the last 3 years, with the following results. f is the corresponding frequency.X 1 2 3 4 5 f 14 18 12 5 1How many drivers are represented in the sample?
选项：
A: 5
B: 15
C: 18
D: 50
答案: 【 50】
3、单选题：
A type of vertical bar chart in which the categories are plotted in the descending rank order of the magnitude of their frequencies is called a
选项：
A: contingency table.
B: Pareto diagram.
C: dot plot.
D: pie chart.
答案: 【 Pareto diagram.】
4、单选题：
The width of each bar in a histogram corresponds to the
选项：
A: differences between the bounaries of the class.
B: number of observations in each class.
C: midpont of each class.
D: percentage of observations in each class.
答案: 【 differences between the bounaries of the class.】
5、单选题：
When polygons or histograms are constructed, which axis must show the true zero or "origin"?
选项：
A: The horizontal axis.
B: The vertical axis.
C: Both the horizontal axis and vertical axis.
D: Neither the horizontal nor the vertical axis.
答案: 【 The vertical axis.】
6、单选题：
A professor of economics at a small Texas university wanted to determine what year in school students were taking his tough economics course. Shown below is a pie chart of the results. What percentage of the class took the course prior to reaching their senior year?
选项：
A: 14%
B: 44%
C: 54%
D: 86%
答案: 【 86%】
7、单选题：
When constructing charts, the following is plotted at the class midpoints:
选项：
A: frequency histograms.
B: percentage polygons.
C: cumulative relative frequency ogives.
D: All of the above.
答案: 【 percentage polygons.】
8、单选题：
A survey was conducted to determine how people rated the quality of programming available on television. Respondents were asked to rate the overall quality from 0 (no quality at all) to 100 (extremely good quality). The stem-and-leaf display of the data is shown below.Stem Leaves3 2 4 4 0 3 4 7 8 9 9 95 0 1 1 2 3 4 56 1 2 5 6 67 0 189 2What percentage of the respondents rated overall television quality with a rating of 50 or below?
选项：
A: 11
B: 40
C: 44
D: 56
答案: 【 44】
9、单选题：
The following are the durations in minutes of a sample of long-distance phone calls made within the continental United States reported by one long-distance carrier.Time (in minutes) Relative Frequency0 but less than 5 0.37 5 but less than 10 0.22 10 but less than 15 0.15 15 but less than 20 0.10 20 but less than 25 0.07 25 but less than 30 0.07 30 or more 0.02 If 1,000 calls were randomly sampled, how many calls laasted under 10 minutes?
选项：
A: 220
B: 370
C: 410
D: 590
答案: 【 590】
10、单选题：
A sample of 200 students at a Big-Ten university was taken after the midterm to ask them whether they went bar hopping the weekend before the midterm or spent the weekend studying, and whether they did well or poorly on the midterm. The following table contains the results. Did Well in Midterm Did Poorly in MidtermStudying for Exam 80 20Went bar hopping 30 70 If the sample is a good representation of the population, we can expect percent of the students in the population to spend the weekend studying and do poorly on the midterm.
选项：
A: 10
B: 20
C: 45
D: 50
答案: 【 10】
第三章用数值度量描述数据
第三章测验题
1、单选题：
Which ofthe following statistics is not a measure of central tendency?
选项：
A: Arithmetic mean.
B: Median.
C: Mode.
D: Q3.
答案: 【 Q3.】
2、单选题：
Which of the arithmetic mean, median, mode, and geometric mean are resistant measures of central tendency?
选项：
A: The arithmetric mean and median only.
B: The median and mode only.
C: The mode and geometric mean only.
D: The arithmetic mean and mode only.
答案: 【 The median and mode only.】
3、单选题：
In a right-skewed distribution
选项：
A: the median equals the arithmetic mean.
B: the median is less than the arithmetic mean.
C: the median is larger than the arithmetic mean.
D: none of the above.
答案: 【 the median is less than the arithmetic mean.】
4、单选题：
In a perfectly symmetrical bell-shaped "normal" distribution
选项：
A: the arithmetic mean equals the median.
B: the median equals the mode.
C: the arithmetic mean equals the mode.
D: All of the above.
答案: 【 All of the above.】
5、单选题：
In general, which of the following descriptive summary measures cannot be easily approximated from a box-and-whisker plot?
选项：
A: The variance.
B: The range.
C: The interquartile range.
D: The median.
答案: 【 The variance.】
6、单选题：
The smaller the spread of scores around the arithmetic mean,
选项：
A: the smaller the interquartile range.
B: the smaller the standard deviation.
C: the smaller the coefficient of variation.
D: All the above.
答案: 【 All the above.】
7、单选题：
In right-skewed distributions, which of the following is the correct statement?
选项：
A: The distance from Q1 to Q2 is larger than the distance from Q2 to Q3.
B: The distance from Q1 to Q2 is samller than the distance from Q2 to Q3.
C: The arithmetic mean is samller than the median.
D: The mode is larger tan the arithmetic mean.
答案: 【 The distance from Q1 to Q2 is samller than the distance from Q2 to Q3.】
8、单选题：
In perfectly symmetrical distributions, which of the following is NOT a correct statement?
选项：
A: The distance from Q1 to Q2 equals to the distance from Q2 to Q3.
B: The distance from the smallest observation to Q1 is the same as the distance from Q3 to the largest observation.
C: The distance from the smallest observation to Q2 is the same as the distance from Q2 to the largest observation.
D: The distance from Q1 to Q3 is half of the distance from the smallest to the largest observation.
答案: 【 The distance from Q1 to Q3 is half of the distance from the smallest to the largest observation.】
9、单选题：
In left-skewed distributions, which of the following is the correct statement?
选项：
A: The distance from Q1 to Q2 is smaller than the distance from Q2 to Q3.
B: The distance from the smallest observation to Q1 is larger than the distance from Q3 to the largest observation.
C: The distance from the smallest observation to Q2 is smaller than the distance from Q2 to the largest observation.
D: The distance from Q1 to Q3 is twice the distance from Q1 to Q2.
答案: 【 The distance from the smallest observation to Q1 is larger than the distance from Q3 to the largest observation.】
10、单选题：
According to the emperical rule, if the data from a "bell-shaped" normal distribution, percent of the observations will be contained within 2 standard deviations around the arithmetic mean.
选项：
A: 68.26
B: 88.89
C: 93.75
D: 95.44
答案: 【 95.44】
第四章抽样分布SamplingDistributions
第四章测验题
1、单选题：
Sampling distributions describe the distribution of
选项：
A: parameters.
B: statistics.
C: both parameters and statistics.
D: neither parameters nor statistics.
答案: 【 statistics.】
2、单选题：
The standard error of the mean
选项：
A: is never larger than the standard deviation of the population.
B: decreases as the sample size increases.
C: measures the variability of the mean from sample to sample.
D: All of the above.
答案: 【 All of the above.】
3、单选题：
The Central Limit Theorem is important in statistics because
选项：
A: for a large n, it says the population is approximately normal.
B: for any population, it says the sampling distribution of the sample mean is approximately normal, regardless of the sample size.
C: for a large n, it says the sampling distribution of the sample mean is approximately normal, regardless of the shape of the population.
D: for any sized sample, it says the sampling distribution of the sample mean is approximately normal.
答案: 【 for a large n, it says the sampling distribution of the sample mean is approximately normal, regardless of the shape of the population.】
4、单选题：
If the expectation of a sampling distribution is located at the parameter it is estimating, then we call that sampling distribution
选项：
A: unbiased.
B: minimum variance.
C: biased.
D: random.
答案: 【 unbiased.】
5、单选题：
For air travelers, one of the biggest complaints is of the waiting time between when the airplane taxis away from the terminal until the flight takes off. This waiting time is known to have a skewed-right distribution with a mean of 10 minutes and a standard deviation of 8 minutes. Suppose 100 flights have been randomly sampled. Describe the sampling distribution of the mean waiting time between when the airplane taxis away from the terminal until the flight takes off for these 100 flights.
选项：
A: Distribution is skewed-right with mean=10 minutes and standard error=0.8 minutes.
B: Distribution is skewed-right with mean=10 minutes and standard error=8 minutes.
C: Distribution is approximately normal with mean=10 minutes and standard error=0.8 minutes.
D: Distribution is approximately normal with mean=10 minutes and standard error=8 minutes.
答案: 【 Distribution is approximately normal with mean=10 minutes and standard error=0.8 minutes.】
第五章点估计PointEstimation
第五章测验题
1、填空题：
If X has the binomial distribution with the number of total trials n=10 and the probability of success 
. In an experiment, we observed 4 successes, then an estimate of 
= .
答案: 【 0.4】
2、填空题：
The diameter of a ball follows a normal distribution with mean m and standard deviation s. Now we randomly draw 6 balls from a batch of product produced in a day and measure the diameter of each ball. We have the following observations (unit: mm): 14.70, 15.21, 14.90, 14.91, 15.32, 15.32. Then, an unbiased estimate of m= .(correct to the second decimal place)
答案: 【 15.06】
3、填空题：
The diameter of a ball follows a normal distribution with mean m and standard deviation s. Now we randomly draw 6 balls from a batch of product produced in a day and measure the diameter of each ball. We have the following observations (unit: mm): 14.70, 15.21, 14.90, 14.91, 15.32, 15.32. Then, an unbiased estimate of 
= .(correct to the third decimal place)
答案: 【 0.067】
4、填空题：
The diameter of a ball follows a normal distribution with mean m and standard deviation s. Now we randomly draw 6 balls from a batch of product produced in a day and measure the diameter of each ball. We have the following observations (unit: mm): 14.70, 15.21, 14.90, 14.91, 15.32, 15.32. Then, a maximum likelihood estimate of 
= .(correct to the third decimal place)
答案: 【 0.056】
5、填空题：
Suppose that X has the following probability distribution:X123p q^22 q(1- q)(1- q)^2 where q (0< q<1) is an unknown parameter. Now we obtain x1=1, x2=2, x3=1. Then a moment estimate of q= .(correct to the second decimal place)
答案: 【 0.83】
6、填空题：
Suppose that X follows the following distribution:X123p q^22 q(1- q)(1- q)^2 where q (0< q<1) is an unknown parameter. Now we obtain x1=1, x2=2, x3=1. Then a maximum likelihood estimate of q= .(correct to the second decimal place)
答案: 【 0.83】
第六章区间估计ConfidenceInterval
第六章测验题
1、单选题：
The width of a confidence interval estimate for a proportion will be
选项：
A: narrower for 99% confidence than for 95% confidence.
B: wider for a sample size of 100 than for a sample size of 50.
C: narrower for 90% confidence than for 95% confidence.
D: narrower when the sample proportion is 0.50 than when the sample proportion is 0.20.
答案: 【 narrower for 90% confidence than for 95% confidence.】
2、单选题：
The head librarian at the Library of Congress has asked her assistant for an interval estimate of the mean number of books checked out each day. The assistant provides the following interval estimate: from 740 to 920 books per day. If the head librarian knows that the population standard deviation is 150 books checked out per day, approximately how large a sample did her assistant use to determine the interval estimate?
选项：
A: 2
B: 3
C: 12
D: It cannot be determined from the information given.
答案: 【 It cannot be determined from the information given.】
3、单选题：
If you were constructing a 99% confidence interval of the population mean based on a sample of n = 25, where the standard deviation of the sample s = 0.05, the critical value of t will be
选项：
A: 2.7969
B: 2.7874
C: 2.4922
D: 2.4851
答案: 【 2.7969】
4、单选题：
When determining the sample size for a proportion for a given level of confidence and sampling error, the closer to 0.50 that p is estimated to be, the __________ the sample size required.
选项：
A: smaller
B: larger
C: sample size is not affected.
D: The effect cannot be determined from the information given.
答案: 【 larger】
5、单选题：
Private colleges and universities rely on money contributed by individuals and corporations for their operating expenses. Much of this money is put into a fund called an endowment, and the college spends only the interest earned by the fund. A recent survey of 8 private colleges in the United States revealed the following endowments (in millions of dollars): 60.2, 47.0, 235.1, 490.0, 122.6, 177.5, 95.4, and 220.0. Summary statistics yield 
=180.975 and s=143.042. Calculate a 95% confidence interval for the mean endowment of all the private colleges in the United States, assuming a normal distribution for the endowments.
选项：
A: $180.975
$94.066
B: $180.975$99.123
C: $180.975$116.621
D: $180.975$119.586
答案: 【 $180.975$119.586】
6、单选题：
A university dean is interested in determining the proportion of students who receive some sort of financial aid. Rather than examine the records for all students, the dean randomly selects 200 students and finds that 118 of them are receiving financial aid. Use a 90% confidence interval to estimate the true proportion of students who receive financial aid.
选项：
A: 0.59
0.068
B: 0.590.057
C: 0.590.087
D: 0.590.048
答案: 【 0.590.057】
7、单选题：
A university dean is interested in determining the proportion of students who receive some sort of financial aid. Rather than examine the records for all students, the dean randomly selects 200 students and finds that 118 of them are receiving financial aid. If the dean wanted to estimate the proportion of all students receiving financial aid to within 3% with 99% reliability, how many students would need to be sampled?
选项：
A: n = 1,844
B: n = 1,784
C: n = 1,503
D: n = 1,435
答案: 【 n = 1,784】
8、单选题：
An economist is interested in studying the incomes of consumers in a particular region. The population standard deviation is known to be $1,000. A random sample of 50 individuals resulted in an average income of $15,000. What is the width of the 90% confidence interval?
选项：
A: $232.60
B: $364.30
C: $465.23
D: $728.60
答案: 【 $465.23】
9、单选题：
An economist is interested in studying the incomes of consumers in a particular region. The population standard deviation is known to be $1,000. A random sample of 50 individuals resulted in an average income of $15,000. What sample size would the economist need to use for a 95% confidence interval if the width of the interval should not be more than $100?
选项：
A: n= 1537
B: n= 385