Finding the Fourth Proportional to 128,018.61, 176,665.57 and 71,429.98

Step by Step Solution

1. Step 1: Write the proportion equation
   128,018.61 : 176,665.57 = 71,429.98 : x
2. Step 2: Convert to fraction form
   128,018.61/176,665.57 = 71,429.98/x
3. Step 3: Cross multiply
   128,018.61x = 176,665.57 × 71,429.98
4. Step 4: Simplify right side
   128,018.61x = 12,619,217,774.64
5. Step 5: Solve for x
   x = 12,619,217,774.64/128,018.61
6. Step 6: Final answer
   x = 98,573.31