Finding the Fourth Proportional to 99,721.37, 137,666.25 and 77,009.37

Step by Step Solution

1. Step 1: Write the proportion equation
   99,721.37 : 137,666.25 = 77,009.37 : x
2. Step 2: Convert to fraction form
   99,721.37/137,666.25 = 77,009.37/x
3. Step 3: Cross multiply
   99,721.37x = 137,666.25 × 77,009.37
4. Step 4: Simplify right side
   99,721.37x = 10,601,591,182.76
5. Step 5: Solve for x
   x = 10,601,591,182.76/99,721.37
6. Step 6: Final answer
   x = 106,312.13