Finding the Fourth Proportional to 390,215.82, 538,486.83 and 229,068.30

Step by Step Solution

1. Step 1: Write the proportion equation
   390,215.82 : 538,486.83 = 229,068.30 : x
2. Step 2: Convert to fraction form
   390,215.82/538,486.83 = 229,068.30/x
3. Step 3: Cross multiply
   390,215.82x = 538,486.83 × 229,068.30
4. Step 4: Simplify right side
   390,215.82x = 123,350,262,720.49
5. Step 5: Solve for x
   x = 123,350,262,720.49/390,215.82
6. Step 6: Final answer
   x = 316,107.80