Proportionate stratified random sampling involves selecting a sample from each group or stratum that is proportionate to the size of the overall population, using the same sampling fraction. Disproportionate stratified random sampling selects a sample from each stratum that is not proportionate to the overall population size, using different sampling fractions for each group.

8. Proportionate stratified random
sampling: The sample chosen from
each stratum is proportionate to
the size of total population with
similar sampling fraction.
Disproportionate stratified random
sampling: The sample chosen from each
stratum is not in proportion to the size of
the total population. The different strata
have dissimilar sampling fraction.

10. Number of subjects in target population (N)
Size of sample(n)