Methods of Research – Descriptive
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the following set of numbers:
2, 4, 4.5,
6, 7.3, 7.9, 9, 10
Calculate the mean: 6.34
Calculate the median: 6.65
the variance: 6.45
Calculate the standard deviation: 2.54
add one number to the set, 30, so
that we have the following set:
2, 4, 4.5,
6, 7.3, 7.9, 9, 10, 30
Calculate the mean and variance of the updated set: Mean: 8.97, Variance: 61.04
the means and variances of the set from Questions 1 and 2; which set’s
descriptive statistics do you think represent the set of numbers best? Why?
The first set, because the
substantial size of the outlier number skewed the data to the right.
3. Take a
look at the following table, which presents statistics on the public’s support
for tax cuts (higher == more support), divided between Democrats and
Republicans. The measure is a basic 7-point scale question, with 1 indicating no support for tax cuts and
7 indicating complete support for tax cuts.
Explain, in plain English, the statistics for each party, being sure to compare
the stats from Democrats and Republicans.
does the standard deviation tell us about each party’s tendency to support (or
not support) tax cuts?
According to the standard deviation
Republicans are more likely to support tax cuts than Democrats.
c. Can we
be absolutely certain that the mean of one of the parties shown here is
higher/lower than the other, given these statistics? Explain why or why not.
Yes, because we are given the