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Title: A group of biology students are assisting a researcher from the University of Toronto on a project. Post by: zlr on Jun 5, 2015 A group of biology students are assisting a researcher from the University of Toronto on a project. They are trying to determine the growth rate of frogs in a marsh near Owen Sound. There are 200 frogs in the first year. By the time the students are in grade 12, 40 frogs were born, 90 died and 5 frogs immigrated. Determine the growth rate.
This is my attempt. I used this formula: [(births + immigration)] – (death + emigration)]/initial population size x 100% = [(40+5) - (90+0)]/200 x 100% = -45/200 x 100% = -0.225 x 100% = -22.5% Probably a dumb question but can you have a negative rate of change? I don't feel like it's right... :s Should I have used the formula λ = N (t + 1)/N (t) instead? Thank you so much for the help! Title: A group of biology students are assisting a researcher from the University of Toronto on a project. Post by: bio_man on Jun 6, 2015 Probably a dumb question but can you have a negative rate of change? Yes, you can. Should I have used the formula λ = N (t + 1)/N (t) instead? What do these variables stand for? Title: A group of biology students are assisting a researcher from the University of Toronto on a project. Post by: zlr on Jun 15, 2015 Probably a dumb question but can you have a negative rate of change? Yes, you can. Should I have used the formula λ = N (t + 1)/N (t) instead? What do these variables stand for? lambda = rate of geometric growth N = initial population t = time |