The axis at the base of the bars is the horizontal axis. The
label of this axis is Price per Bushel, with each data group being
a different dollar amount, from $1 to $5. The data are grouped
into dollar amounts. In this case the groups are $1, $2, $3, $4,
The scale is the range of frequency values shown on the graph. The span of values represented is determined by the lowest and greatest values you wish to include on the graph.
When looking at this axis, look to see where the range begins and ends, as well as at the interval between tick marks. Determining the scale of this axis will be discussed in more detail in a later section of this unit.
The vertical axis is the quantity demanded given in units of bushels.
In this case, the frequency scale goes from 0 to 80, and uses an interval of units of 10. The frequency of our data groups range over nearly the entire scale so we are able to get a good picture of our data.
Once we have a good idea of what data is contained in a graph we can compare the different bars.
Things to be looking for: can we see any trends; how easy is it to determine individual data values; could the data be distorted? Answering these questions requires an understanding of how scale is determined for a bar graph.
In this graph we can see that the bar heights range from about 10% of the height of the graph, to the full height, so the scale appears to be appropriate for the given data.
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