Finding the Fourth Proportional to 128,643.72, 177,536.52 and 72,058.56

Step by Step Solution

1. Step 1: Write the proportion equation
   128,643.72 : 177,536.52 = 72,058.56 : x
2. Step 2: Convert to fraction form
   128,643.72/177,536.52 = 72,058.56/x
3. Step 3: Cross multiply
   128,643.72x = 177,536.52 × 72,058.56
4. Step 4: Simplify right side
   128,643.72x = 12,793,025,978.61
5. Step 5: Solve for x
   x = 12,793,025,978.61/128,643.72
6. Step 6: Final answer
   x = 99,445.40