Exam 2- sampling distributions Flashcards
Approximate sampling distribution of x- bar is
The distribution of x- bar values obtained from repeatedly taking SRSs of the same size from the same population
Theoretical sampling distribution of x- bar is
The distribution of all x- bar values from all possible samples of the same size from the same population
Center
The mean of the sampling distribution of x- bar …. the mu….
Equals ….. Population mean
Mean =mu is valid for
All sample sizes and populations of all shapes
Spread
The standard deviation of the sampling distribution of x- bar …..
Equals the standard deviation of the population divided by the square root of n
Valid for all sample sizes and population of all shapes
Shape
For non-normal population
Shape of sampling distribution of x-bar is approximately normal when n is large
Shape
For normal population
Shape of the sampling distribution if x- bar is exactly normal for any n
Mean …… equals mu regardless of population shape or sample size
Exactly
Standard deviation of x- bar is always ….. Than the standard deviation of the population for samples of any size where ….
Less. n>1
Standard deviation of c- bar gets ….as n increases at rate ….
Smaller…. Square root of n
To cut standard deviation in half
Quadruple sample size
Shape is normal if population is …..for any sample size
Normal
Shape is approximately normal if we take a …… ……. ……. from a non- normal population
Large random sample
The population distribution of a variable is
The distribution of values of the variable among all the individuals in the population
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