Stat & Prob SEMI-FINALS S2

• N - Population Size
• sample - representative portion of the population
• n - Sample size
• Element or sampling unit - Each member in the sample unit
• random sampling - each member of the population has a nonzero chance to be selected as a subject
• Simple Random Sampling - used if all the units in the population are homogenous.
• Lottery Method - each member of the population is assigned a unique number
• Sampling with replacement - upon selecting a unit at random from the population, the unit is returned to the population.
• Sampling without replacement - the unit selected at random from the population is not included in the next Selection.
• Systematic Sampling - , the sampling interval k is determined by getting the quotient of population size N and sample size n.
• stratified sampling - used if the population is not homogeneous.
• Cluster sampling - used if the population is very large.
• Multi-stage Sampling - the population is divided into hierarchy of units, and sampling is done successively.
• Parameter - a number that summarizes the data from an entire population.
• statistic - a number summarize the data from a sample.
• statistical Hypothesis - a statement regarding an unknown population parameter.
• null Hypothesis - the hypothesis being tested.
• Alternative Hypothesis - the operational statement of the conjecture that the proponent believes to be true and wishes to investigate.
• Alternative hypothesis - It is a statement contradictory to the mll hupothesis.
• statistical test - is done to make a decision whether the null hypothesis should be rejected or not.
• The numerical value obtained from a statistical test is called the test statistic
• Type 1 Error - the error of rejecting the null hypothesis when in fact it is true
• Туре II Error - a type Il error is the error committed when we decide not to reject the mull hypothesis when in reality the null hypothesis is fake.
• Power of the test - The probability of not committing a Type I error
• In statistics, the word "significance" means " not by chance" or

  "probably true".