Finding the Fourth Proportional to 3,902.72, 5,382.72 and 2,505.60

Step by Step Solution

1. Step 1: Write the proportion equation
   3,902.72 : 5,382.72 = 2,505.60 : x
2. Step 2: Convert to fraction form
   3,902.72/5,382.72 = 2,505.60/x
3. Step 3: Cross multiply
   3,902.72x = 5,382.72 × 2,505.60
4. Step 4: Simplify right side
   3,902.72x = 13,486,943.23
5. Step 5: Solve for x
   x = 13,486,943.23/3,902.72
6. Step 6: Final answer
   x = 3,455.78