Finding the Fourth Proportional to 124,081.72, 171,141.12 and 78,720.64

Step by Step Solution

1. Step 1: Write the proportion equation
   124,081.72 : 171,141.12 = 78,720.64 : x
2. Step 2: Convert to fraction form
   124,081.72/171,141.12 = 78,720.64/x
3. Step 3: Cross multiply
   124,081.72x = 171,141.12 × 78,720.64
4. Step 4: Simplify right side
   124,081.72x = 13,472,338,496.72
5. Step 5: Solve for x
   x = 13,472,338,496.72/124,081.72
6. Step 6: Final answer
   x = 108,576.34