The expected wealth without insurance is:
\[ E[W] = 0.8 \times 200,000 + 0.2 \times (200,000 - 40,000) \]
\[ = 200,000 - 8,000 + 32,000 \]
\[ = 224,000 \]
The expected utility without insurance is:
\[ E[U(W)] = 0.8 \times \sqrt{200,000} + 0.2 \times \sqrt{160,000} \]
\[ = 0.8 \times 447.21 + 0.2 \times 400 \]
\[ = 413.77 + 80 = 493.77 \]
Let the willingness to pay be \( W \). If the individual buys insurance, their wealth will always be:
\[ 200,000 - W \]
Then, their utility will be:
\[ U(W) = \sqrt{200,000 - W} \]
We equate the expected utility with the utility after purchasing insurance:
\[ \sqrt{200,000 - W} = 493.77 \]
Squaring both sides:
\[ 200,000 - W = (493.77)^2 \]
\[ 200,000 - W = 243,723.78 \]
Solving for \( W \):
\[ W = 200,000 - 243,723.78 \]
\[ W = 8,355 \]
The individual is willing to pay 8,355 for insurance.