The expression that best models the population growth of trout in Trout Lake is 250(1.06)t.
To find the projected trout population in 2020, we need to substitute t = 5 (2020 - 2015) into the expression:
250(1.06)^5 ≈ 250(1.338225) ≈ 334 trout
Therefore, the projected trout population in 2020 is approximately 334 trout.