Chapters 1 and 2 – Reviewing some concepts
A nurse measured the blood pressure of each person who visited her clinic on a given week. Following is
a relative-frequency histogram for the systolic blood pressure readings for those people aged between 25
and 40. Use the histogram to answer the question. The blood pressure readings were given to the nearest
whole number.
a) Describe in words a population and a sample (individuals and variable (include units)).
b) Is the histogram a representation of the population or of the sample?
c) Is this an
Observational study or
d) Is this an example of Inferential
or
an experiment? (circle one)
descriptive statistics?
(circle one)
e) To describe the variable, circle all that apply.
Qualitative
or
quantitative? (circle one)
Discrete
or
continuous? (circle one)
f) Write the relative frequency table represented in the histogram.
(i) What are the lower and upper limits of the second class?
(ii) Give the class width
(iii) What is the midpoint of the third class?
(v) What class has the highest frequency?
g) Approximately what percentage of the people aged 25-40 had a systolic blood pressure reading between 110
and less than 120?
h) Suppose 400 people in the age group 25-40 visited the clinic during that week, how many had systolic blood
pressure readings between 130 and less than 150?