If the population distribution is skewed,in most cases the sampling distribution of the sample mean can be approximated by the normal distribution if the samples contain at least 30 observations.

Population Distribution

The spread of people across locations, often analyzed for understanding demographics or economic conditions.

Skewed

describes a distribution that is not symmetrical, with a longer tail on one side of the peak than the other.

Normal Distribution

A probability distribution that is symmetrical around the mean, showing that data near the mean are more frequent in occurrence than data far from the mean.