Variable – an attribute that can be measured
One-variable data sets – give measures of one
attribute for each person/thing
*examples of situations where you see
one-variable data – tally charts, frequency tables, bar graphs, Histograms, Pictographs,
Circle Charts
Two-variable data sets – give measures of
two attributes for each item in a sample.
*Examples of situations where two-
variable data sets are seen are ordered
pairs, scatter plots, two-column tables
of values
State whether each situation involves one-variable or two-variable data. Justify your
answers.
1) Jesse measures the amount of precipitation
each month in Kitchener.
Solution: you can use mean, median and mode to analyse the data so it is a one-variable
situation (also, there is only one attribute
being measured for each month)
2) The study involves statistics about the poverty level in a community and the level of
education.
Solution: The study involves two pieces of data
for each person/family so it is a two-variable
situation (finding relationships between the variables)
a) What type of graph would be best to show
how many hours the students worked during
the week? Justify your answer.
b) What type of graph would be best to
show the relationship between the
number of hours a student spends at
work during the week and weekend.
Justify your answer.
P.133 #1a, 2, 3, 5, 8