数据分析5(1).doc

Question 1
Consider the width of two bootstrap confidence intervals constructed based on the same sample. One of the ins.
Inorrect

If the data were collected on the same day, the industry would not matter.
50 observations is not enough to be able to consider the data as paired.
When random sampling is involved, data can't be treated as paired.
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Question ExplanationThis question refers to the following learning objective(s):
Define observations as paired if each observation in one dataset has a special correspondence or connection with exactly one observation in the other data set.
Carry out inference for paired data by first subtracting the paired observations from each other, and then treating the set of differences as a new numerical variable on which to do inference (such as a confidence interval or hypothesis test for the average difference)
Question 3
Which of the following is false about bootstrap and sampling distributions?
Your Answer
Score
Explanation
Bootstrap distributions are centered at the sample statistic, sampling distributions are centered at the population parameter.
Both distributions get narrower as the standard deviation decreases.
Both distributions are comprised of sample statistics.
Both distributions are created by sampling with replacement from the population.
Correct

The bootstrap distribution is created by sampling with replacement from the original sample, not the population.
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Question ExplanationThis question refers to the following learning objective(s): Describe how bootstrap distributions are constructed, and recognize how they are different from sampling distributions.
Question 4
A study examining the relationship between weight of school children (4th to 6th graders) found a 95% confidence interval for the difference between the average number of school days missed by overweight and normal weight children (
μoverweight−μ