sampling fraction การใช้

• The formula above for the margin of error assume that there is an infinitely large sampling theory, this assumption is reasonable when the sampling fraction is small.
• To adjust for a large sampling fraction, the fpc factored into the calculation of the margin of error, which has the effect of narrowing the margin of error.
• The margin of error for a particular sampling method is essentially the same regardless of whether the population of interest is the size of a school, city, state, or country, as long as the sampling fraction is less than 5 %.