*A Positively Skewed Distribution*

*David C. Howell*

An example that we will look at several times in the future comes from a study
by Mireault (1990) investigating the effects of the death of a parent on the emotional
well-being of college students. Among other things, she asked three different groups of
college students to rate the perceived vulnerability to loss--i.e., how vulnerable did
they feel about the loss of someone important to them. The three groups were (1) a group
who had had a parent die before they started college, (2) a group whose parents had
divorced, and (3) a group whose parents were both alive and still married to each other.
Download these data from Mireault.dat . There are many
variables here. They are, in order, ID, Group, Gender, YearColl, College, GPA, LostPGen,
AgeAtLos, SomT, ObsessT, SensitT, DepressT, AnxT, HostT, PhobT, ParT, PsycT, GSIT,
PVTotal, PVLoss, SuppTotl. We are interested in Group and PVLoss. The other variables will
come up in other exercises.

- Plot the data on PVLoss for all groups combined. If your software gives you the option,
superimpose a normal distribution on top of the plot as a reference.
- Calculate the descriptive statistics for these data and see how they are reflected in
the plot.
- Obtain the descriptive statistics and histogram for each group separately.
- Create a boxplot for these data separated by groups.
- Do these data lead you to suspect that loss of a parent leads to emotional changes in
the children?
- How does loss through death seem to compare to loss through divorce?
- How, can you relate the shape of the distribution of the complete set of data to the
differences between groups?

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Last modified: 6/30/98