pictographs - linn-benton community college get inspired...
TRANSCRIPT
Pictographs
• A pictograph is a type of graph in which
pictures, symbols, or icons represent
quantities.
• Pictographs can represent data in
interesting ways, but they can also be
misleading.
Example 10
• This pictograph
predicts the world
population.
• Each person icon
represents 1 billion
people.
Example 11 • Each hotdog represents 10% of campers.
Example 12 • This pictograph compares amounts spent on
different types of holiday gifts.
Example 13 • Why is this pictograph misleading?
Example 13, cont’d
• Solution: The bars are not proportional in
height to the amounts they represent.
• For example, there were nearly 4 times as many
students in grades 1-8 as there were in pre-
elementary.
• The bar representing grades 1-8 is only about 3
times as tall as the one representing pre-
elementary students.
• This causes the difference to look smaller than it
really is.
Example 14 • Why is this pictograph misleading?
Example 14, cont’d
• Solution: The bars are not proportional
to the amounts they represent.
• The bars are also angled, emphasizing
the length of the top bar and making the
bottom bar look shorter.
Example 15
• Why is this pictograph misleading?
Example 15, cont’d
• Solution: It must be clear whether a 2-
dimensional or 3-dimensional object is being
used to represent a quantity.
• The amount of milk sold in 2003 was about twice
the amount sold in 1997.
• It is not clear whether the volume or the height of
the carton represents the milk quantity.
• The volume of the second carton is 8 times as
large as the volume of the first carton. This is
misleading.