Finding the Fourth Proportional to 2,285.10, 3,153.78 and 1,290.47

Step by Step Solution

1. Step 1: Write the proportion equation
   2,285.10 : 3,153.78 = 1,290.47 : x
2. Step 2: Convert to fraction form
   2,285.10/3,153.78 = 1,290.47/x
3. Step 3: Cross multiply
   2,285.10x = 3,153.78 × 1,290.47
4. Step 4: Simplify right side
   2,285.10x = 4,069,842.71
5. Step 5: Solve for x
   x = 4,069,842.71/2,285.10
6. Step 6: Final answer
   x = 1,781.03