Simple interest formula:

A = P(1 + it) where P is the amount of principal to be invested, i is the interest rate, t is the time, and A is the amount accumulated with interest.

Plugging in our numbers, we get:

400 = P(1 + 0.08(8))

400 = P(1 + 0.64)

400 = 1.64P

1.64P = 400

Typing this problem into our search engine, we get:

P =

**$243.90**