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1. Write a summary to compare the following three
sampling techniques: random sampling, subjective sampling
and voluntary sampling.
2. Now a days there are many
online surveys. An online weapon store posted an
online
survey to ask individuals the question "Should
government impose more restricted laws for possessing guns?
Yes or No. " After one year of online surveying, the
store summarized the data and found that 90% of the
responses said "NO". The online company then gave this
information to their lobbyist to lobby against "more
restricted laws for possessing guns." Discuss the
flaws of the survey techniques.
3. If you were going to conduct an online survey,
describe some strategies that will be able
to give you a
representative sample of your target population.
4. Download a random sample of 50 cases from the
Activity Sampling database.
a) Draw side-by-side histograms and stem-and-leaf
plots for the average number of squares from students
selection and the random selection. The population
average number of
squares are given in your class.
b) Compare the centers of the histograms with the
actual population average, which one is closer?
c) Compare the spreads of the average number of
squares between the student's selection and the random
selection, which is smaller?
5. Suppose you select 30 boxes instead of 10 boxes
and the computer also selects 30 boxes. Now compare
the average number of squares from your selected boxes and
form the random selection with the actual population average
of the number of squares. Do you think that
your
average number of squares or the average number of squares
from random selection is closer to the true population
average? Why? |
