Finding the Fourth Proportional to 428,775.50, 643,028.31 and 155,186.39

Step by Step Solution

1. Step 1: Write the proportion equation
   428,775.50 : 643,028.31 = 155,186.39 : x
2. Step 2: Convert to fraction form
   428,775.50/643,028.31 = 155,186.39/x
3. Step 3: Cross multiply
   428,775.50x = 643,028.31 × 155,186.39
4. Step 4: Simplify right side
   428,775.50x = 99,789,238,881.56
5. Step 5: Solve for x
   x = 99,789,238,881.56/428,775.50
6. Step 6: Final answer
   x = 232,730.74