Exercise 4 Page 257

Through the use of a circle graph, we want to show the change of the number of hits for our school's new website based on the given table during these 5 months.

Month	Hits
August	250
September	320
October	485
November	650
December	925

Let's recall what a circle graph displays. They show data as parts of a whole. This means that, to create a circle graph, we need to divide the number of hits for each month by the overall number of hits. The overall number of hits is the sum of each month.

Month	Hits	Percentage
August	250	250/2630*100 %≈ 9.5 %
September	320	320/2630*100 %≈ 12.2 %
October	485	485/2630*100 %≈ 18.4 %
November	650	650/2630*100 %≈ 24.7 %
December	925	925/2630*100 %≈ 35.2 %
Sum	2630	100 %

Now we can plot the circle graph using these percentages.

The circle graph does not show the exact number of hits each month and it is difficult to track how this number changes over time. Therefore, this data display is not appropriate for this situation. It was a nice try, though.

Extra

Types of Data Displays

Let's recall the types of data displays we can use to describe a data set.

Data Display	When Do We Use It?
Pictograph	To show data using pictures
Dot Plot	To show the number of times each value occurs in a data set
Stem-and-Leaf Plot	To show how ordered numerical data are distributed
Box-and-Whisker Plot	To show the variability of a data set by using quartiles
Circle Graph	To show data as parts of a whole
Bar Graph	To show frequencies of data values in specific categories
Histogram	To show frequencies of data values in intervals of the same size
Line Graph	To show how data change over time
Scatter Plot	To show the relationship between two data sets using ordered pairs plotted in a coordinate plane

Hints

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