Finding the Fourth Proportional to 61,381.60, 86,109.20 and 61,381.60

Step by Step Solution

1. Step 1: Write the proportion equation
   61,381.60 : 86,109.20 = 61,381.60 : x
2. Step 2: Convert to fraction form
   61,381.60/86,109.20 = 61,381.60/x
3. Step 3: Cross multiply
   61,381.60x = 86,109.20 × 61,381.60
4. Step 4: Simplify right side
   61,381.60x = 5,285,520,470.72
5. Step 5: Solve for x
   x = 5,285,520,470.72/61,381.60
6. Step 6: Final answer
   x = 86,109.20