2-7 Bar Graphs & Histograms. Pages 85-89. Indicators D1 -Read and create graphs D2 -Analyze how decisions about graphing affect the graphical representation. What is the difference between a bar graph and a histogram?. There are two differences
D1 -Read and create graphs
D2 -Analyze how decisions about graphing affect the graphical representation
There are two differences
Bar graphs are usually used to display "categorical data", that is data that fits into categories.
For example suppose that I
offered to buy donuts for six
people and three said they
wanted chocolate covered,
2 said plain and
one said with
icing & sprinkles.
Histograms are usually used to present "continuous data", that is data that represents measured quantity where, at least in theory, the numbers can take on any value in a certain range.
A good example is weight. If you measure the
weights of a group of adults you might
get and numbers between 90 lbs. and
240 lbs. We usually report our weight as
pounds or to the nearest 1/2 lb. but we
might do so to the nearest 1/10 lb.
depending on how accurate the scale is.
# of people
90 I 150 I 210 I
The weight data would then be collected into categories to present a histogram.
might be a histogram for weights (with the appropriate scale on the vertical axis). Here the data has been collected into categories of 30 lbs.
Pg. 88 #14-16 and Pg. 569 #1-4