Finding the Fourth Proportional to 124,082.72, 171,142.50 and 78,721.64

Step by Step Solution

1. Step 1: Write the proportion equation
   124,082.72 : 171,142.50 = 78,721.64 : x
2. Step 2: Convert to fraction form
   124,082.72/171,142.50 = 78,721.64/x
3. Step 3: Cross multiply
   124,082.72x = 171,142.50 × 78,721.64
4. Step 4: Simplify right side
   124,082.72x = 13,472,618,273.70
5. Step 5: Solve for x
   x = 13,472,618,273.70/124,082.72
6. Step 6: Final answer
   x = 108,577.72