# PreCalculus

A lake formed by a newly constructed dam is stocked with 1,000 fish. Their population is expected to increase according to the logistic curve
N=30/(1+29e^-1.35t)
where N is the number of fish, in thousands, expected after t years. The lake will be open to fishing when the number of fish reaches 20,000. How many years, to the nearest year, will this take?

1. 👍 0
2. 👎 0
3. 👁 133
1. well, just solve for t:

20 = 30/(1+29e^-1.35t)
1+29e^-1.35t = 1.5
e^-1.35t = 0.5/29
-1.35t = -4.060
t = 3

1. 👍 0
2. 👎 0
posted by Steve

## Similar Questions

1. ### math

If P0 > c (which implies that −1 < a < 0), then the logistics function P(t) = c 1 + ae−bt decreases as t increases. Biologists often use this type of logistic function to model populations that decrease over time. See the

asked by Anonymous on September 18, 2014
2. ### Trigonometry

If P0 > c (which implies that −1 < a < 0), then the logistics function P(t) = c 1 + ae−bt decreases as t increases. Biologists often use this type of logistic function to model populations that decrease over time. See the

asked by Anonymous on September 18, 2014
3. ### algebra

The number of bass in a lake is given by P(t) = 2800/1+6e^-0.05t where t is the number of months that have passed since the lake was stocked with bass. (a) How many bass were in the lake immediately after it was stocked? ? bass

asked by Barb on November 17, 2014
4. ### Engineering Math Growth

I am having trouble figuring out where to start with this one. Biologists stocked a lake with 40 ﬁsh and estimated the carrying capacity (the maximal population for the ﬁsh of that species in that lake) to be 300. (a) Assume

asked by Erica on September 26, 2016
5. ### biology

A researcher wanted to know how many fish were in a dam.He caught 20 fish and marked them by clipping out a small section of their tail fins.He then released them back into dam.A few days later he caught 25 fish and found that 8

asked by jeremy on October 16, 2015
6. ### college algebra

fish population: the fish population in a certain lake rises and falls according to the formula F=1000(30+17t-t^2) , Here F is the number of fish at time t, where t is measured in years since January 1, 2002, when the fish

asked by sheen on October 8, 2015
7. ### Physics

The hoover dam produces 2x10 to the 9 W of electricity. It is composed of 7x10 to the 9 kg of concrete. To produce 1 kg of concrete requires 1 MJ of energy. How much energy did it take to produce the dam? How long was the "energy

asked by Ellen on February 2, 2011
8. ### Algebra

The number of bass in a lake is given by P(t) = 2800/1 + 6e^−0.05t where t is the number of months that have passed since the lake was stocked with bass. (a) How many bass were in the lake immediately after it was stocked? 400

asked by Kimberly on November 17, 2014
9. ### Calculus

When a reservoir is created by a dam,50 fish are introduced into the reservoir ,which has an estimated carrying capacity of 8000 fish. A logistic model of the population is P(t)= 400,000 / 50 + 795e^-0.5t , where t is measured in

asked by Dash on April 5, 2014
10. ### Physics

An engineer decides to use a successful dam design for a new lake of the same depth. If the new lake has ten times the surface area as the lake held by the original dam, what, if any, design changes are necessary for the new dam

asked by Supansa on May 5, 2016

More Similar Questions