Inferential Statistics

Inferential statistics is the second major area of statistics. Here, the statistician tries to make inferences from samples to populations. Inferential statistics uses probability.
The area of inferential statistics called hypothesis testing is a decision making process for evaluating claims about a population based on information obtained from samples, that is, we use the information contained in the sample to learn about the large population."A population consist of all subjest (human or otherwise) that are being studied. Many - times populations can be very large. In order to save time and money, statisticians may study only a part of population, called a sample i.e.,". A sample is a group of subjects selected from population.

 

Inference methods can only be applied when it is reasonable to assume that the data in hand are representative for the question being considered about a large group. A data set may contain representative information for certain questions but not for others.
The fundamental rule for using data for inferences about a much larger group if the data can be considered to be representative and unbiased, statisticians uses different sampling methods.

Sampling theory and data collection
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