Finding the Fourth Proportional to 99,391.98, 137,211.72 and 76,679.98

Step by Step Solution

1. Step 1: Write the proportion equation
   99,391.98 : 137,211.72 = 76,679.98 : x
2. Step 2: Convert to fraction form
   99,391.98/137,211.72 = 76,679.98/x
3. Step 3: Cross multiply
   99,391.98x = 137,211.72 × 76,679.98
4. Step 4: Simplify right side
   99,391.98x = 10,521,391,945.37
5. Step 5: Solve for x
   x = 10,521,391,945.37/99,391.98
6. Step 6: Final answer
   x = 105,857.55