Finding the Fourth Proportional to 428,973.32, 643,464.57 and 129,456.59

Step by Step Solution

1. Step 1: Write the proportion equation
   428,973.32 : 643,464.57 = 129,456.59 : x
2. Step 2: Convert to fraction form
   428,973.32/643,464.57 = 129,456.59/x
3. Step 3: Cross multiply
   428,973.32x = 643,464.57 × 129,456.59
4. Step 4: Simplify right side
   428,973.32x = 83,300,725,800.69
5. Step 5: Solve for x
   x = 83,300,725,800.69/428,973.32
6. Step 6: Final answer
   x = 194,186.26