On January 1, 1879, Records Show That 500 of a Fish

question 29

Multiple Choice

On January 1, 1879, records show that 500 of a fish called Atlantic striped bass were introduced into the San Francisco Bay.In 1899, the first year fishing for bass was allowed, 100,000 of these bass were caught, representing 10% of the population at the start of 1899.Owing to reproduction, at any moment in time the bass population is growing at a rate proportional to the population at that moment.Assume that when fishing starts in 1899, the rate at which bass are caught is proportional to the square of the population with constant of proportionality $10^{-6}$ .Write a differential equation satisfied by B(t) , for t > 20.

• A) \(\frac{d B}{d t}=7.6 B-10^{-6} B^{2}\)
• B) \(\frac{d B}{d t}=7.6 B-\frac{10^{-6}}{B^{2}}\)
• C) \(\frac{d B}{d t}=0.38 B-10^{-6} B^{2}\)
• D) \(\frac{d B}{d t}=0.38 B-\frac{10^{-6}}{B^{2}}\)

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Definitions:

Neutral Stimulus

A stimulus that initially does not elicit any intrinsic response until it is paired with an unconditioned stimulus in classical conditioning.

Conditioned Stimulus

A previously neutral stimulus that, after association with an unconditioned stimulus, comes to trigger a conditioned response.

Unconditioned Response

A natural, automatic reaction to a stimulus that occurs without prior learning or conditioning.

Conditioned Response

A learned reaction to a previously neutral stimulus, established through classical conditioning.