chapter 2 Flashcards
what is a database?
a collection of information
what is data called that has 2 variables?
bivariate data
what does a pictogram use?
symbols or pictures to represent a number of items
in a bar chart…
- bars are equal widths with equal spaces between them
- the height (or length) of the bar represents the frequency
what is a vertical line graph?
similar to a bar chart- has lines instead of bars
what do multiple bar charts have?
more than one bar for each class
in a composite bar chart what does each bar show?
how the total frequency for that category is made up from different component groups
what does a stem & leaf diagram show?
numerical data- split into a “stem” and “leaves”
how are the numbers written in a stem & leaf diagram?
in order
what does the stem & leaf diagram show?
the shape of the data distribution
what does a back to back stem & leaf diagram show?
two sets of data with the same stem
on back to back stem & leaf diagram where are the smallest values on each row?
nearest to the stem
a pie chart is a way to display data in what way?
when you want to show how something is shared/divided
what does a pie chart use to represent frequency?
area
what do the angles at the centre of the pie chart add up to?
360 degrees
in a pie chart, what is the area of the sector proportional to?
proportional to the frequency of the category
what is the area of the pie chart proportional to?
the total frequency
if two sets of data have different frequencies and they were drawn the same size- why is this bad?
it is misleading
what are areas in comparative pie charts like?
the area of the 2 pie charts are in the same ratio as the two frequencies