In a pond 100 fish were caught and examined for levels of mercury. Of this sample, 25 fish were found to have unhealthy levels of mercury. If we use this sample as an estimate, and we know the population of the pond to be 5,000 fish, what is the approximate number of fish in the pond that have healthy levels of mercury?	Options
A) 2,150 B) 750 C) 1,250 D) 3,750 E) 2,500
Let D = fish population of the pond = 5,000,   B = fish population of the sample = 100,   A = fish sample with healthy level of mercury = 100 - 25= 
<gadget id="calculator">100 - 25</gadget>
<output>75</output>
75, and   C= fish population with healthy level of mercury, then:   Proportion: A/B = C/D   Proportion: 75/100 = C/5,000   C = 3,750. There are approximately 3,750 healthy fish in the pond.   Answer is 3,750
<result>D</result>
In a pond 100 fish were caught and examined for levels of mercury. Of this sample, 25 fish were found to have unhealthy levels of mercury. If we use this sample as an estimate, and we know the population of the pond to be 5,000 fish, what is the approximate number of fish in the pond that have healthy levels of mercury?