1. 1 Press Ctrl-A ©G Dear 2008 – Not to be sold/Free to use EstimatingPopulations Stage 6 - Year 11 General Mathematics Preliminary

2. 2 Estimating Populations (1/2) Capture-Recapture Technique Used to estimate populations that cannot be accurately counted with ease. Method 1.A sample population is captured, tagged and released. 2.A second sample is captured and the % tagged represent the first sample. 3.The Unitary method is then used to estimate the whole population.

3. 3 1% of population = 300  20 20% of population = 300 deer Estimating Populations (2/2) Capture-Recapture Technique Example A population of deer in the Ghost rd area are to be estimated. A sample of 300 deer are captured, tagged and released in to the forest. Another sample of 150 deer are caught and 30 had tags. Estimate the population. Percentage Tagged = 30 / 150 x 100% Tagged 2 nd sample Number of dear in second sample = 20% Original Sample 100% of population = 300  20  100 = 1 500 deer