The Amazon River Basin Includes the Largest Remaining Connected Area

question 22

Essay

The Amazon River basin includes the largest remaining connected area of tropicalforest in the world, and ecologists regularly monitor its health. One aspect of itshealth is the density of different indigenous species. The Amazon basin includes bothareas that are periodically flooded, and areas that are not periodically flooded. If thedensities of species differ in the flooded and unflooded regions, researchers will wantto take stratified samples in their studies. Stratified sampling would be moreexpensive, since boats must be rented to get to any randomly selected flooded sites.The data below are measures of density (individuals per square kilometer) of primatesin random samples of flooded and unflooded areas in the Amazon basin. a) Do these data provide convincing evidence of a difference in the primate densityin flooded and unflooded forests in Amazonia?
Provide appropriate statisticaljustification for your conclusion.b) Based on your results in part (a), would you recommend using a stratified sample?
Justify your recommendation with a statistical argument.

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Definitions:

Inventory

The sum of all products and materials possessed by a firm, intended for either reselling or manufacturing.

Statement of Cash Flows

A financial report detailing the inflow and outflow of cash and cash equivalents for a business.

Direct Method

A cash flow statement preparation technique that lists all major operating cash receipts and payments for the period.

Bonds

Financial securities that represent a loan made by an investor to a borrower, typically corporate or governmental.