Which statement about the formula for the lower quartile is correct?

The correct statement regarding the formula for calculating the lower quartile is that it is expressed as (n+1)/4. This formulation is based on the fundamental idea that statistical quartiles divide a dataset into four equal parts, and it incorporates the total number of data points in the sample, n.

When using the (n+1)/4 formula, you add one to the total number of observations, allowing for a more accurate representation of the position in the ordered dataset where the lower quartile can be found. This adjustment is important because it ensures that the quartiles are calculated solely based on the number of observations, which leads to a more accurate division of the dataset.

This method is particularly useful for both small and large datasets, since it works by providing a positional calculation based on where the lower quartile lies rather than adjusting the overall structure of the dataset itself. The other options do not properly represent how quartiles are calculated, as they either underrepresent or misrepresent the necessary adjustments needed for accurate placement within the set.