1- Statistics Flashcards
What is primary data?
Data collected by the user directly; user is aware of the conditions under which data was collected
What is secondary data?
Data provided by third parties
What is categorical data?
Data put in categories e.g. colours
What is ordinal data?
Data in a distinct order e.g. first, second, third
What is a sample?
A set of data that represents the population
What is a random sample?
A sample where every item has an equal chance of selection
What is Quota sampling?
A sample up to a given number
What is Stratified sampling?
Structuring the data in the quota to represent the population i.e. the same weighting
What is Convenience sampling?
The easiest to collect
What is Judgement sampling?
Choosing data which best represents the population
What is Snowball sampling?
Choosing through referrals of other subjects
What is standard deviation?
Tells us how far on average the data deviates from the mean
What is variance?
Standard deviation squared
What is the formula for geometric mean?
n√[(1+x1)x…x(1+xn)] - 1
What is the formula for correlation coefficient?
Cov(x,y)/σxσy
