Texas A&M University (TAMU) STAT 201 Elementary Statistical Inference Exam 1 Practice

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• Compute the sample mean for the data set 2, 4, 6, 8, 10.
• What does variation refer to in data values?
• Which statement is true about cause-and-effect in observational studies versus randomized experiments?
• Which statement best describes a statistic?
• Interpret the first quartile (Q1) in the context of a data set.
• Which method uses a random starting point and a fixed interval between selections?
• In experimental design, what do 'treatments' refer to?
• In the Bonds example, what was the computed mean of the home runs?
• What does the whisker in a box plot represent?
• If a z-score is 2, approximately what percentile is the data point in a standard normal distribution?
• What is an experimental unit?
• Which of the following is a continuous quantitative variable?
• Which description best defines convenience sampling?
• In the aspirin trial, what are experimental units?
• A random starting point is chosen and every 50th student is selected until 75 students are included. What type of sampling is this?
• In the dataset described above, 3 occurs 5 times in a dataset of 20 observations. What is the relative frequency of the data value 3?
• What does a box plot represent in data visualization?
• Which statement about sampling with replacement is true?
• What is a sample?
• Which is not a protection mandated by law?
• The distance from home to the nearest grocery store is best described as:
• What is undue influence in data collection?
• The variable 'ethnicity' is an example of which type?
• Which statement about sample size issues is NOT accurate?
• Which statement correctly characterizes a lurking variable?
• What is the function of a control group in an experiment?
• A systematic sample is obtained by:
• Which statement about sampling error is true?
• What is confounding?
• What is population?
• The term for the most frequent value in a data set is
• Which element is most crucial to support a causal conclusion in a randomized experiment?
• Which statement about ethics requires IRB approval?
• In the formula z = (X - μ)/σ, what does μ represent?
• In the cluster sampling example involving college departments, what is the correct description of the process?
• What is one common purpose of transforming data to z-scores?
• In a frequency table, what does the Frequency column represent?
• In the aspirin trial, what is the explanatory variable?
• Self-selected samples commonly exhibit what issue?
• Which statement best differentiates lurking variables from explanatory variables?
• In stratified sampling, which statement is true?
• In the stratified sampling example with five departments and a total of 50, selecting 10 from each department illustrates which approach?
• In the aspirin trial, what is the response variable?
• Which statement about quartile computation is true?
• A bin in a histogram represents what?
• What is a parameter?
• Which description best defines cluster sampling?
• Which sequence correctly describes the steps to estimate a population parameter from a sample?
• In a pie chart, which statement is true?
• Which scenario describes non-response bias?
• Which of the following best describes a z-score with a positive sign?
• In stratified sampling, the population is divided into homogeneous subgroups, and samples are drawn from each subgroup. This statement is:
• Which of the following constitutes a misleading use of data?
• Statistical fraud: which statement is true?
• Which statement about a randomized experiment with a placebo is true?
• In what situation is a small sample often unavoidable?
• Which of the following is a measure of spread rather than a measure of center?
• If the 60th percentile of a data set is 85, which statement is true?
• In the formula i = k/4(n+1) used to locate a quartile, what does k represent?
• Which statement best characterizes a simple random sample?
• Descriptive statistics describe data using what?
• Which term describes equal allocation in stratified sampling?
• Which statement correctly defines a placebo?
• Which value is NOT part of the five-number summary?
• What is the frequency of the data value 6 in the dataset?
• Which statement best defines a variable?
• The data type for 'number of correct answers on a quiz' is:
• The freshman, sophomore, junior, and senior years are treated as four groups; two years are selected randomly and all students in those two years are surveyed. What type of sampling is this?
• In a randomized experiment, which statement about outcomes is true?
• Which statement best defines relative frequency?
• What is the meaning of the sample mean?
• Which statement correctly describes the relationship between a statistic and a parameter?
• In constructing a histogram, what is the first step?
• If a value has z-score 0, what does that indicate?
• Which term describes the organization and summarizing of data?
• How does a z-score help compare values from different distributions?
• Which of the following is a data point in that study?
• In the aspirin heart attack study, what is the population?
• Which statement best distinguishes bar graphs from histograms?
• Which statement accurately contrasts stratified and cluster sampling?
• If two variables are related, does one cause the other?
• If a data point has z-score -1.5, where is it relative to the mean?
• Which sampling method selects a first random starting point and then selects every kth item in a list?
• Continuing the plant growth example, which variable is the response variable?
• Which statement best describes the effect of random assignment in a randomized experiment?
• Stem-and-leaf plot is defined as
• In the described systematic sampling, what is the interval between selections?
• Which statement describes a placebo?
• Which statement best distinguishes sampling errors from non-sampling errors?
• Which statement is true about both stratified and cluster sampling?
• In a distribution that is perfectly symmetrical, which relation between mean and median holds?
• Which analogy is correct: parameter is to population as statistic is to sample?
• In descriptive statistics, what is done with data?
• Using the same frequency table, what is the total number of observations?
• A survey divides the population into freshmen, sophomores, juniors, and seniors, then selects 25 students from each group. What type of sampling is this?
• Which sequence correctly describes how to compute the sample standard deviation?
• A histogram with a longer left tail describes which distribution?
• A staff member stands in front of the library and asks the first 100 undergraduate students he encounters about tuition costs. What type of sampling is this?
• The variable 'movie rating: excellent, good, fair, poor' is best described as:
• An observational study is best described as an investigation that:
• Which statement about variation is true?
• If data range is 0 to 100 and you want 5 bins, the bin width is:
• Which statement describes a stratified sampling plan?
• In the aspirin trial, what is the sample?
• Which statement best defines blinding in a randomized trial?
• In cluster sampling, which describes the process?
• To compute a z-score, which parameters are used—assuming you are standardizing with population values?
• Which statement is true about quartiles and percentiles?
• The data type for 'IQ scores' is classified as:
• In the aspirin trial, what are treatments?
• A bar graph is best described as:
• Which scenario would likely produce a z-score of approximately 2?
• What is sampling with replacement?
• What does a z-score represent?
• Which description matches convenience sampling?
• Given Q1 = 194,250 and Q3 = 649,000, what is the interquartile range (IQR) of the data set?
• In the Bonds home runs example, how many data values were analyzed?
• Which statement about small samples is true?
• If a data value is drawn at random from the dataset, what is the probability of obtaining 4?
• Which statement about the interquartile range (IQR) is true?
• Which of the following is the five-number summary?
• Which statement about quartiles is true?
• In the Knoll Academy example, which term best describes the group '100 families w/ kids at Knoll Academy'?
• Describing data aims to
• In a box plot, which statement is true about identifying outliers using the 1.5 IQR rule?
• Which statement best characterizes a histogram?
• In the same dataset, what is the relative frequency of data value 5?
• Which statement correctly characterizes a z-score?
• Which statement best describes the interquartile range (IQR)?
• When the index i is a decimal, the quartile value is found by averaging the two neighboring data values. If i equals 6.6, which two data values are averaged?
• Which of the following best describes a statistic?
• Which formula represents a z-score for a value X in a population?
• In an experiment, the researcher typically does which of the following?
• Which term refers to a subset of the population that has the same characteristics as the population of interest?
• Which statement defines a sample?
• Which statement correctly describes the interquartile range (IQR)?
• What is sampling bias?
• Regarding self-funded or self-interest studies, which statement is true?
• Why do we standardize data when comparing values from different data sets?
• In a time series line graph, which of the following is true?
• Distribution is defined as
• In the 16-ounce can example, measurements vary due to measurement differences or manufacturing tolerance.
• What does frequency mean in data analysis?
• Which statement best describes the placebo effect in an experiment?
• To prove that the explanatory variable is causing a change in the response variable, what is necessary?
• Which measure is generally preferred as a center when there are outliers because it is not affected by extreme values?
• In the frequency table for a dataset with data values 2, 3, 4, 5, 6, 7 having frequencies 3, 5, 3, 6, 2, 1, respectively, what is the total number of observations?
• Which statement is true about a z-score of 0?
• Given a dataset with a starting point of 10 and a bin width of 5, what is the bin boundary for k = 3?
• Which statement about sampling error is generally true?
• In the Bonds example, what was the computed standard deviation?
• What is sampling without replacement?
• A completely random method is used to select 75 students, giving every undergraduate in the fall semester the same probability of selection. What type of sampling is described?
• Standard deviation is best described as
• Biased samples give results that are inaccurate and not valid. Which statement best describes the issue with biased samples?
• Which of the following is an example of misleading use of data?
• Which statement describes how a statistic is used to estimate a population parameter?
• In statistical terms, the mean of the sample is called a:
• If the 70th percentile of a test score is 16, what does this imply?
• Which practice is recommended when comparing data from different datasets due to different scales?
• Which sampling method gives every member of the population an equal chance of being chosen?
• A z-score indicates how many standard deviations a data point is from what?
• Which z-score is most extreme relative to the mean?
• What characteristic distinguishes an experiment from an observational study?
• In the dataset described above, which data value has the highest frequency?
• Which term refers to formal methods for drawing conclusions from data?
• Which statement best describes percentile within a distribution?
• Which statement describes double-blinding?
• What is probability defined as?
• If the mean is greater than the median, the data are typically
• An outlier is best described as:
• Which statistic corresponds to the 50th percentile?
• Using i = k/100 (n+1) with k in {25, 50, 75}, which statement is true?
• Which statement describes confounding in research?
• In observational studies, cause-and-effect relationships are usually...
• In an experimental study, which statement best describes the explanatory variable?
• What is the first step in constructing a box plot?
• A data set that has two values with the highest frequency is described as
• Which statement describes cluster sampling?