Finding the Fourth Proportional to 99,638.72, 137,539.80 and 72,992.86

Step by Step Solution

1. Step 1: Write the proportion equation
   99,638.72 : 137,539.80 = 72,992.86 : x
2. Step 2: Convert to fraction form
   99,638.72/137,539.80 = 72,992.86/x
3. Step 3: Cross multiply
   99,638.72x = 137,539.80 × 72,992.86
4. Step 4: Simplify right side
   99,638.72x = 10,039,423,365.83
5. Step 5: Solve for x
   x = 10,039,423,365.83/99,638.72
6. Step 6: Final answer
   x = 100,758.25