Finding the Fourth Proportional to 61,131.20, 85,480 and 61,131.20

Step by Step Solution

1. Step 1: Write the proportion equation
   61,131.20 : 85,480 = 61,131.20 : x
2. Step 2: Convert to fraction form
   61,131.20/85,480 = 61,131.20/x
3. Step 3: Cross multiply
   61,131.20x = 85,480 × 61,131.20
4. Step 4: Simplify right side
   61,131.20x = 5,225,494,976
5. Step 5: Solve for x
   x = 5,225,494,976/61,131.20
6. Step 6: Final answer
   x = 85,480