Finding the Fourth Proportional to 2,505.47, 3,755.81 and 860.85

Step by Step Solution

1. Step 1: Write the proportion equation
   2,505.47 : 3,755.81 = 860.85 : x
2. Step 2: Convert to fraction form
   2,505.47/3,755.81 = 860.85/x
3. Step 3: Cross multiply
   2,505.47x = 3,755.81 × 860.85
4. Step 4: Simplify right side
   2,505.47x = 3,233,184.73
5. Step 5: Solve for x
   x = 3,233,184.73/2,505.47
6. Step 6: Final answer
   x = 1,290.45