This paper offers class mark estimators for the intervals of a grouped frequency distribution, derived by parabolic interpolation between any given interval and its adjacent intervals. The objective ...

Tallying is a way of recording data that counts in groups of five. The data is tallied as it is counted, with a mark for each piece of data, and then the frequency is recorded at the end. Frequency ...

Characterization of the distribution of intervals between successive births affords both practical and theoretical advantages in the analysis of fertility data. Moreover, attempts to formulate a ...