Page 180 - MAT KS3 Y8 Cambridge CheckPoint

18 Interpreting and discussing results

When you study statistics, you need to be able to draw and Key words
understand charts, graphs, tables and diagrams. This is a very
important skill. Looking at a ‘picture’ of data makes it easier to see Make sure you learn and
what it is showing you. understand these key words:
line graph
For example, look at the table on the right. It shows the number of
trend
boxes of breakfast cereal sold at a grocery store each month from
stem-and-leaf diagram
January to June. It also shows which shelf the boxes were on when they
were on sale in the store. There is a lot of information in
Number of boxes of breakfast cereal sold
the table but it is difficult to understand just by looking at
it. However, when the data is put into a bar chart showing Jan Feb Mar Apr May Jun
the total monthly sales, you can now see that May had the Top shelf 30 33 28 23 44 22
largest number of sales by quite a long way. Total sales in Middle shelf 32 52 46 40 65 51
all the other months were all very similar. Bottom shelf 26 10 20 35 24 14

Sales of breakfast A pie chart that just shows the
cereals according shelf where the cereals were Monthly breakfast cereal sales at a grocery store
to position on shelves placed, when they were on sale,
Jun
is also helpful. You can clearly see
Bottom Top that nearly half the boxes sold
shelf shelf had been on the middle shelf. May
The fewest boxes were sold when
Middle
shelf they were on sale on the bottom Month Apr
shelf. Mar

When the data is put into a line graph showing the Feb
monthly sales and the positions on the shelf, you can
Jan
see that the sales from the middle shelf were always
greater than sales from the other shelves. The sales 0 20 40 60 80 100 120 140
from the top and bottom shelves were quite close to Number of boxes sold
each other on some occasions.

Monthly breakfast cereals sales at a grocery store
from May to June
Top shelf Middle shelf Bottom shelf

70 All this information could be important to a grocery store
Number of boxes sold 50 when it plans where to place items to get maximum sales.
60
40
It could also help the store decide in which months it needs
30
to order extra stock.
20
10
frequency diagrams, pie charts, line graphs and stem-and-
0 In this unit you will learn how to draw and interpret
Jan Feb Mar Apr May Jun leaf diagrams. You will also learn how to draw conclusions
Month from data that is presented in different ways.
178 18 Interpreting and discussing results