Finding the Fourth Proportional to 139,789.20, 192,911.40 and 76,128.24

Step by Step Solution

1. Step 1: Write the proportion equation
   139,789.20 : 192,911.40 = 76,128.24 : x
2. Step 2: Convert to fraction form
   139,789.20/192,911.40 = 76,128.24/x
3. Step 3: Cross multiply
   139,789.20x = 192,911.40 × 76,128.24
4. Step 4: Simplify right side
   139,789.20x = 14,686,005,357.94
5. Step 5: Solve for x
   x = 14,686,005,357.94/139,789.20
6. Step 6: Final answer
   x = 105,058.23