Sampling Distributions Flashcards
What is a Parameter?
A parameter is a number that describes the population, as opposed to the sample.
*In statistical practice, the value of a parameter is not known because we cannot examine the entire population. *
What is a Statistic?
A statistic is a number that can be computed from the sample data.
In practice, we often use a statistic to estimate an unknown parameter.
What is the Population Distribution of a variable?
The population distribution of a variable is the distribution of values of the variable among all the individuals in the population.
What is the Sampling Distribution of a statistic?
The sampling distribution of a statistic is the distribution of values taken by the statistic in all possible samples of the same size from the same population.
Caution: A sampling distribution does not describe the individuals of a population. Sampling distribution describes how a statistic varies in many samples from the population.
What is the Central Limit Theorem?
Draw an SRS of size n from any population with mean μ and finite standard deviation σ. The central limit theorem says that when n is large, the sampling distribution of the sample mean is approximately Normal:
What is Statical Control?
A variable that continues to be described by the same distribution when observed over time is said to be in statistical control, or simply in control.
