Pie Charts

A survey of a group of 360 people shows the brand of handphones they use. The results of the survey are presented in the table below.

Handphone brand
Apple iPhone
Nokia
RIM BlackBerry
Others
No handphone
Number of people
90
180
36
45
9


From the above, the fraction of the group that uses:
  • Apple iPhone
:   90
360
  =  1
4
  • Nokia
:  180
360
  =  1
2
  • RIM BlackBerry
:   36
360
  =   1 
10
  • Other handphones
:   45
360
  =  1
8
  • No handphone
:   9 
360
  =   1 
40
Now, let's take all these fractions and present them in a more readable form so they are easy to compare. We'll use what we call a pie chart as below.




The above circle graph known as a pie chart shows the popularity of handphone brands among the group.

Now, let's answer some questions based on the above pie chart.

a)  Which was the most popular handphone brand? Explain.
 Nokia; because it got the biggest pie in the pie chart - half the pie.


1
4
  or 25% is marked by a
right angle in the pie chart.
b)  What percentage of the group used the Apple iPhone?
 
1 whole pie  =  100%
1
4
 of a pie  =  25%
 25% of the group used Apple iPhone.


c)  How many times as many people used Nokia handphones as compared to those who used Apple iPhone?
 
Nokia  1
2
Apple iPhone  1
4
     1
2
  ÷  1
4
=1
2
  ×  4
1
    =    2
2 times as many people used Nokia handphones as compared to those who used Apple iPhone.


d)  What percentage of the people surveyed used RIM BlackBerry?
 
 1 
10
  ×  100%  =  10%
 10% of the people surveyed used RIM BlackBerry.