Normal distribution Flashcards
1
Q
What is Standard Deviation?
A
It is a measure of the spread of data using every item of data. It is especially useful when comparing value from different sets of data and when analysing the position of data in a normal population.
+It uses all the data.
-It takes longer to calculate than the range or interquartile range if you do not use a calculator.
2
Q
How much of the Data is within 1 standard Deviations of the Mean?
A
About 2/3 of the data.
3
Q
How much of the Data is within 2 standard Deviations of the Mean?
A
About 95% of the data.
4
Q
How much of the Data is within 3 standard Deviations of the Mean?
A
Virtually all (99.7%) of the data.
