Math 143 C/E, Spring 2001
IPS Reading Discussion Questions
Chapter 1, Section 2 (pp. 40-58)
- Demonstrate how to find the median, first and
third quartiles for each of the following
situations (you can make up your own data in
each case):
- there are 9 observations (that is,
n = 9)
- n = 10
- n = 15
- n = 16
- Does it make sense to talk about shape,
center and spread for
categorical data? Why or why not?
- What is an outlier? Why is it so
important to pay attention to outliers?
- List by name the measures of center that are
discussed in this section. What measures of
spread are mentioned? Which of these measures
(both of center and of spread) are resistant
and which are not?
- What percentile is the median? the first
and third quartile? Consider the shopping data
provided at the top of p. 12 (the raw data, not
the stemplot). Determine which purchase totals
lie below the 40th percentile.
- Give an example (that is, make up your own) of
a 5-number summary that might result from a set
of data that is skewed to the left.
Draw the boxplot that corresponds to your
5-number summary.
- Since you are being introduced to two distinct
ways of measuring center/spread, it is reasonable
to expect that, in some cases you would want to
use one method, and in other cases the other
method is preferable. Describe the types of
data for which each of the methods is best suited.
- What is the relationship between standard
deviation and variance? One of these
is a measure of spread, while the other one is
not. Why is the other one not appropriate as a
measure of spread?
- Calculate by hand the standard deviation for
the data set: