3 Representations Of Data Flashcards
What is an outlier?
An extreme value that lies outside the pattern of the data
Sometimes defined as x>Q3+k(Q3-Q1)
What is an anomaly?
An outlier which should be removed from the data as it is clearly wrong
What is cleaning the data
Removing the anomalies
What do box plots show?
Outliers, boundary for outliers, lower quartile, median, upper quartile and range
How should you plot a cumulative frequency graph?
Plot each point at the upper class boundary for x
How do you work out the frequency density in a histogram?
Freq density=freq/class width
What is a frequency polygon?
Joining the middle of the top of each bar in a histogram forms a frequency polygon.
When comparing data sets what can you comment on?
A measure of location
And
A measure of spread
If the data contains extreme values which comparisons should be used
Median and interquartile range
