What is statistical inference?
Using the data taken from a sample to draw conclusions about the characteristics of a population.
What is a point estimate?
A sample statistic that can be used to estimate the corresponding population value.
What is the sampling error? (When comparing population to sample)
The absolute difference of the sample statistic and the population parameter
What is a sampling distribution?
A probability distribution of a sample statistic. Can be formed when MANY samples of size n are taken from a population.
What are the properties of μx̅ ? (Mean of sample means)
1) μx̅ = μ given a proper sampling distribution
2) Solving for sample standard deviation (see formula sheet)
3) σx̅ is the standard error of the MEANS
What are the three main characteristics of he central limit theorem (CLT)?
1) A sample (taken from the population with replacement) is NORMALLY DISTRIBUTED when its sample size is large enough (n>30)
2)By the law of large numbers, the larger the sample size, the better the approximation
3) If a population is normally distributed, the sampling distribution will be as well (FOR ALL N)
REVIEW: Difference between population parameter and sample statistic?
Sample statistic: A value calculated from the sample data. Serves as an ESTIMATE for the population parameter.
Population parameter: The actual mean value we want. Have to estimate USING the sample statistic.
