Finding the Fourth Proportional to 390,196.01, 538,311.12 and 309,298.88

Step by Step Solution

1. Step 1: Write the proportion equation
   390,196.01 : 538,311.12 = 309,298.88 : x
2. Step 2: Convert to fraction form
   390,196.01/538,311.12 = 309,298.88/x
3. Step 3: Cross multiply
   390,196.01x = 538,311.12 × 309,298.88
4. Step 4: Simplify right side
   390,196.01x = 166,499,023,815.99
5. Step 5: Solve for x
   x = 166,499,023,815.99/390,196.01
6. Step 6: Final answer
   x = 426,706.12