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There are 2,100 bacteria in a circular petri dish. The dish has a radius of 40 millimeters. What is the approximate population density? (Use 3. 14 for π) Area of a circle = πr2 0. 02 bacteria per square millimeter 0. 42 bacteria per square millimeter 2. 39 bacteria per square millimeter 52. 5 bacteria per square millimeter.

User Wendyl
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1 Answer

10 votes

Answer:

B) 0.42

Explanation:

population density=number of people/square units

we plug in 2,100 for the first one but we don't know the second one for that we need the area which is A=π
r^(2) so the radius is 40 millimeters so
40^(2) =1600 1600*π=5024

2,100/5024=0.417 round it up and it is 0.42

so B) 0.42 is the answer

User Waypoint
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