Chapter 2 Flashcards
Explain relational table
A collection of logically related
data that can be retrieved, manipulated, and
updated to meet users’ needs
What are join table
Tables are linked after the primary and foreign keys
have been created
Explain primary key
Each row (record) in a relational database needs to
be uniquely identified by a primary key.
Explain a foreign key
If primary key appears in another table, it is referred
to as the foreign key, which allows for a relationship
to be created
What are the type of Join table
Inner , Left, Right and Full
What are pivot table for
PivotTables summarize and reorganize data.
* Quick and efficient.
* Used in Excel and other data analysis software.
* Aid in creating visualizations.
LO 2.3Copyright © John Wiley & Son, Inc.
What does descriptive statistic do
Descriptive statistics help understand
characteristics of data:
* Average observations in the data
* The data’s shape
* The distribution of the data
Measure of Location
Used to understand average or typical observation in
a data set
Central tendency measures describe a data set by
identifying a central position within the data set. suchas average ,median,mode
Measure of Dispersion
Describe the amount of variation in the data , usually use variation and standard of deviation
Measure of shape
Can reveal the best measure of central tendency to
use or show patterns in the data.
* Data sets are either symmetrical or asymmetrical in
shape.
* Symmetrical distribution: mean, median, and mode are
equal and data distribution to the right of the mean
mirrors data to the left.
* Symmetrical distribution looks like a bell curve.
Whats a histogram
Histogram is a bar chart of a frequency distribution
where height of the bar reflects the frequency within
the interval
Whats Data visualisation
Graphical presentation of data and information.
* Increased focus due to:
* Increase in data availability
* Easy to use software tools
Area chart best practice
represent change over time not use with more 4 categories
Bar column
comparing part to a whole highlight change over, 2-7 categories al a time
Bubble Chart
Compare independant values that have a distinct gap or outliers
