Download Introduction to Chance Models (Section 1.1) Introduction A key step

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Sample quiz #3 (for after Chapters 1 and 2)
1. Which of the following is true about sampling?
a) Larger samples are always better than smaller samples, regardless of how the sample
were collected.
b) Larger samples will have less sampling variability than smaller samples.
c) Larger samples give less biased estimates than smaller samples.
d) Larger samples are needed with larger populations.
2. Recall the Gettysburg Address exploration. Which of the following sampling methods would
be unbiased?
a) Select your sample of words by closing your eyes and dropping a pencil down on the
page, record the word, repeat until you have 10 words.
b) Select your sample of words by cutting each word out of the address, mixing them up in
a hat and drawing out 10 slips of paper.
c) Select your sample of words by typing each word onto the same sized slips of paper,
mixing them up in a hat and drawing out 10 slips of paper.
d) Select your sample of words by randomly choosing words you think represent all the
words in the Gettysburg Address.
3. The following dotplot is the time estimates for a 10 second song snippet we looked at in
class. The highest time estimates were 30 seconds.
Suppose that one of the observations recorded as 30 seconds was a typo, and was meant
to be 20. If we corrected this entry in the dataset, how would the following numerical
statistics change, if at all?
Mean:
SMALLER
SAME
LARGER
Median:
SMALLER
SAME
LARGER
Standard Deviation:
SMALLER
SAME
LARGER
June 27, 2014
MAA PREP workshop
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