Finding the Fourth Proportional to 65,168.72, 89,940.42 and 39,690.02

Step by Step Solution

1. Step 1: Write the proportion equation
   65,168.72 : 89,940.42 = 39,690.02 : x
2. Step 2: Convert to fraction form
   65,168.72/89,940.42 = 39,690.02/x
3. Step 3: Cross multiply
   65,168.72x = 89,940.42 × 39,690.02
4. Step 4: Simplify right side
   65,168.72x = 3,569,737,068.61
5. Step 5: Solve for x
   x = 3,569,737,068.61/65,168.72
6. Step 6: Final answer
   x = 54,776.85