10.1 Calculating Statistics (MATH)

You can use statistics to summarise sets of data.          

You can also use them to compare different sets
of data.

You should already be able to calculate three

different averages: the mode, the media and    

the mean.  

Remember that the range is not an average. It
measures how spread out a set of values or numbers is.

For a large set of data, it is not practical to list every number
separately. instead, you can record the data in a frequency table


Worked Example 10.1 

Question :

The table shown the number of beads on 200 necklaces.
a   Find the mode.
b   Find the mean.
c   Find the range.

Answer : 

a  The mode is 35
    The mode is the number with the highest frequency.

b  6900 : 200 =34.5
    (25 x 34 + 30 x 48 + 35 x 61 + 40 x 30 + 45 x 15 + 50 x 12) : the sum of all the frequencies. This is a reasonable answer because it is near the middle of all the possible number of beads.

c  50 - 25 = 25
   this is the different between the largest and smallest number of beads.