In 1999, US
teens watched television for an average of 12 1/4 hours
per week (Nielson Media Research).
The average earnings
in 1998 for people 18 or older was $16,124
per year (without a high school diploma); $22,895
per year (with a high school diploma ); and $40,478
per year (with a university degree). (US Census Bureau).
On average, fast-food
cooks make $6.29 an hour, service-station
attendants make $7.34 an hour, machinists
make $14.35 an hour, mail carriers
make $16.39 an hour, and physical
therapists make $27.49 an hour (US Bureau of
In 1998, US production workers averaged
34.6 hours per week
on the job. Their average hourly wage was $12.77;
their average weekly earnings were $441.84
(US Bureau of Labor Statistics).
In 1997, the
US metropolitan area with the highest
average annual salary was San Jose, California.
Workers there earned an average of $48,702
per year (US Bureau of Labor Statistics).
In 1998, men with
a bachelors degree earned an average
of $50,272 per year,
while women with a bachelors
degree earned $30,692 (US Census Bureau).
On average, elephants
in captivity live 40 years, guinea pigs 4 years,
and opossums 1 year. Animals in the wild rarely live to
their maximum potential life span.
Whenever a set of data is summarized by
an average or mean, a measure to indicate how the data
are spread around the mean should be reported as well.
One such measure is called the
standard deviation. It describes a
typical amount that the data values may differ from the