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 Activity
For this activity you'll analyze a data set that consists of
the number of births recorded in the U.S. for each day of the year in
1978.
What do you think the distribution of birthdays will be throughout the
year? Many people might answer that its a uniform distribution: you're
just as likely to be born on one day as any other. Still, others,
citing the Spring Fever effect, might say that there will be more
births 9-10 months after Spring (Dec-Feb?)
First, upload this data set into your
favorite data analysis software. If you use Fathom (and we
recommend it for this exercise), you can do this simply by
(1) making sure you're connected to the internet (which I
assume you are if you're reading this!)
(2) starting Fathom
(3) Under the "File" menu, select "Import from URL"
(4) In the dialog box that opens, type the URL that points to
the data: http://inspire.stat.ucla.edu/unit_01/birthdays.txt
This dataset consists of 8 variables. The variable named "births" gives
the number of births on a particular day of the year. The other
variables all have to do with the date on which that number of births
was observed. For example, "date" is the calendar date. "edate" is the
number of elapsed days since Jan 1 1962. "month" gives you the month of
the date, "day" tells you the day of the month, "week" tells you which
week of the year (1 through 52), "dayofweek" is a 0 for Sunday and a 6
for Saturday, and "dayssincejan" tells you how many days the date is
from jan 1 1978.
Use Fathom to explore the data. What can you say about the distribution
of the number of births? Participate in the Blackboard discussion on
this activity.
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