Final answer:
Using Ebbinghaus' Law of Forgetting, the estimated test score after two years from an initial score of 84 with a forgetting constant of 0.3 is approximately 32, rounded to the nearest whole number.
Step-by-step explanation:
Ebbinghaus' Law of Forgetting suggests that memory retention decays over time following a mathematical formula. To estimate a student's biology test score after two years, given an initial score of 84 and a constant c equal to 0.3, we apply the formula:
log(P) = log(P0) − c log(t + 1)
First, convert time in years to months: 2 years = 24 months. Then, plug the values into the formula:
log(P) = log(84) - 0.3 log(24 + 1) = log(84) - 0.3 log(25)
Using a calculator for logarithms:
log(P) ≈ 1.9243 - 0.3(1.3979) ≈ 1.9243 - 0.4194 ≈ 1.5049
Now, raise 10 to the power of each side to solve for P:
P = 10^1.5049 ≈ 10^1.5
P ≈ 31.62
The estimated performance level, or test score, after two years, is approximately 32 when rounded to the nearest whole number.