Finding the Fourth Proportional to 65,443.62, 90,309.67 and 39,992.55

Step by Step Solution

1. Step 1: Write the proportion equation
   65,443.62 : 90,309.67 = 39,992.55 : x
2. Step 2: Convert to fraction form
   65,443.62/90,309.67 = 39,992.55/x
3. Step 3: Cross multiply
   65,443.62x = 90,309.67 × 39,992.55
4. Step 4: Simplify right side
   65,443.62x = 3,611,713,992.96
5. Step 5: Solve for x
   x = 3,611,713,992.96/65,443.62
6. Step 6: Final answer
   x = 55,188.18