Finding the Fourth Proportional to 399,835.72, 599,858.72 and 143,694.15

Step by Step Solution

1. Step 1: Write the proportion equation
   399,835.72 : 599,858.72 = 143,694.15 : x
2. Step 2: Convert to fraction form
   399,835.72/599,858.72 = 143,694.15/x
3. Step 3: Cross multiply
   399,835.72x = 599,858.72 × 143,694.15
4. Step 4: Simplify right side
   399,835.72x = 86,196,186,461.40
5. Step 5: Solve for x
   x = 86,196,186,461.40/399,835.72
6. Step 6: Final answer
   x = 215,579.00