Without further study, you forget things as time passes. A model of human memory gives the percentage, p, of acquired knowledge that a person retains after t weeks. The formula is p = (100 – a)e-bt + a, where a and b vary from one person to another. If a = 18 and b = 0.6 for a certain student, how much information will the student retain two weeks after learning it?

54% or 43%? I keep ending up with 26%

(100-18)e^-.6(2) +18

24.69792538+18
= 42.6

So round up. 43%

To determine the percentage of information retained by the student two weeks after learning it, we can use the given formula: p = (100 – a)e^(-bt) + a.

Substituting the given values a = 18 and b = 0.6 into the formula, we have:

p = (100 – 18)e^(-0.6 * 2) + 18

Simplifying this expression further:

p = 82 * e^(-1.2) + 18

Calculating e^(-1.2) approximately:

e^(-1.2) ≈ 0.301

Substituting this value back into the equation:

p = 82 * 0.301 + 18

Calculating this expression:

p ≈ 24.682 + 18

p ≈ 42.682

Therefore, the student will retain approximately 42.682% of the information two weeks after learning it.

To calculate the percentage of information the student will retain two weeks after learning it, we need to substitute the given values for a and b into the formula and solve for p.

Given:
a = 18
b = 0.6
t = 2 weeks

The formula for retention of knowledge is:
p = (100 - a)e^(-bt) + a

Substituting in the values:
p = (100 - 18)e^(-0.6 * 2) + 18

Using a calculator, calculate the exponential term first, then continue solving:
p = 82e^(-1.2) + 18

Now, we can calculate the value of p:

p ≈ 82 * 0.301194 + 18
p ≈ 24.7073488 + 18
p ≈ 42.7073488

Therefore, the student will retain approximately 42.71% of the information two weeks after learning it.