HEAD CIRCUMFERENCE
Use the following data sets that have been downloaded into your calculator
FHED = Head circumferences of Two-Month-Old Baby-Girls (cm)
MHED = Head circumferences of Two-Month-Old Baby-Boys (cm)
Chapter 1
1) Answer each of the following:
a) Identify the population(s), and variable (Who are we talking about, what are we
measuring?)
There are two different populations:
2 month-old baby boys and
2-month-old baby girls
Variable: Head circumference measured in centimeters
b) Is the variable qualitative or quantitative?
This variable is quantitative
c) Is the variable discrete or continuous?
It is continuous. Between any two values, there is another value which may represent the
head circumference of other 2-month-old baby boy or girl
d) Identify the level of measurement.
Ratio level of measurement
It makes sense to compare head circumferences of 2-month-old-baby-boys (girls) using a
ratio or quotient.
e) What sampling technique could have been used?
(Answers vary) It may be a convenient sample of all 2-month-old-baby-boys and girls
that have been seen by a doctor of a particular clinic
f) Is this an observational study or an experiment?
It is an observational study.
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