Term

Definition
every member of the population has an equal chance of being selected. 


Term

Definition
a sample in which a researcher uses the participants who are available for the study. 


Term

Definition
the difference between a sample statistic and a population parameter. 


Term
the central limit theorem 

Definition
makes predictions about the characteristics of a distribution of sample means. 


Term

Definition


Term

Definition
1. the mean of the sample means is equal to the population m. 2. the SD of the M is equal to the average distance a sample mean is from m. This property is also called the standard error of the mean. 3. the distribution of all sample means, of a given size, forms a normal distribution. 


Term

Definition


Term
standard error of the mean 

Definition
equal to the standard deviation of the sample means 


Term
standard error of the mean 

Definition
sigmaM = sigma/square root N 


Term
impact of sample size on sampling error 

Definition
the sample size has a direct influence on the standard error of the mean.
The larger the sample size, the closer the sample mean will be to the population m. Also, the closer the sample mean is to the population m, the less sampling error will be encountered. 


Term

Definition
the distance an observed mean is from m, expressed in standard units.
not the same as a z score !! 


Term

Definition
z= Mm  sigma M
in words: z statistic = sample mean  population mean. Divided by standard error of the mean. 

