First 254 words of the document:
Tally charts and frequency tables
1.) A tally chart or frequency table can be used to process raw data. They
make it easier to spot patterns.
Cumulative frequency tables
2.) The cumulative frequency of the value of a variable is the total number
of observations that are less than or equal to that value.
Grouping discrete data
3.) If data is widely spread it should be grouped into classes.
Classes of varying width and open-ended classes
4.) When there is an uneven spread of data across the range, class
intervals may vary in width.
5.) When the extreme values of data are not known, the first and/or last
intervals may be left open.
6.) A two-way table displays frequencies for two categories of data.
Other tables and databases
7.) A database is an organised collection of information.
8.) A summary table shows data that has been sorted and summarised. It is
easier to interpret than the original data.
9.) A pictogram uses symbols or pictures to present a certain number of
10.) It must have a key to tell you the number of items represented by a
single symbol or picture.
11.) When drawing a pictogram, make sure that;
Each picture is the same size
The picture can be divided easily to show different frequencies
The spacing between the pictures is the same in each row
You give a key
Other pages in this set
Here's a taster:
12.) In a bar chart, bars of equal width are drawn for each category or
13.) The length of a bar is equal to the frequency of the category it
14.) The gaps between bars must be of equal width.
Vertical line graphs
15.) A vertical line graph is similar to a bar chart except that the bar width is
reduced to a pencil line thickness.
Stem and leaf diagrams
Here's a taster:
Where r1 = radius of first circle
r2 = radius of second circle
F1 = total frequency of the first data set
F2 = total frequency of the second data set
26.) To compare the total frequencies, compare the areas.
27.) To compare proportions, compare the individual angles.…read more