In: Statistics and Probability
What is a sampling distribution of means? How is it created and what is it used for?
Sampling distribution is a probability distribution of sample mean. For example, suppose {1,2,3,4} is a set of population units. So the size of populatio, N=4. Now we draw sample of size 2 without replacement technique from this population and the following table shows the sampling distribution of sample mean:
| Serial no. | Possible samples | Sample mean=![]()  | 
![]()  | 
| 1. | (1,2) | 1.5 | 1/6 | 
| 2. | (1,3) | 2 | 1/6 | 
| 3. | (1,4) | 2.5 | 1/6 | 
| 4. | (2,3) | 2.5 | 1/6 | 
| 5. | (2,4) | 3 | 1/6 | 
| 6. | (3,4) | 3.5 | 1/6 | 
Hence the sampling distribution of 
 is
![]()  | 
1.5 | 2 | 2.5 | 3 | 3.5 | 
![]()  | 
1/6 | 1/6 | 2/6 | 1/6 | 1/6 | 
Since the mean of all sample means (
)
is population mean 
 so sample mean is considered for making inference on population
mean which is unknown.