In the article "Randomized Stratified Sampling Methodology for Water Quality in Distribution Systems" (Journal of Water Resources Planning and Management, Vol. 130, Issue 4, pp. 330-338), V. Speight et al. proposed the method of stratified sampling to collect water samples for water-quality testing. The following table separates the Durham, North Carolina water distribution system into strata based on distance from the nearest treatment plant.

Distance from treatment center ________________________ Stratum size

Less than 1.5 miles .................................................1310

1.5-less than 3.0 miles .............................................3166

3.0-less than 4.5 miles .............................................2825

4.5-less than 6.0 miles .............................................1593

6.0-less than 7.5 miles .............................................1350

7.5 miles or greater .................................................1463

Use the table to design a procedure for obtaining a stratified sample (with proportional allocation) of 80 water samples from Durham.