

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.】
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.】
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.】
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.】
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 est
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