Finding the Fourth Proportional to 2,285.13, 3,153.30 and 1,290.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,285.13 : 3,153.30 = 1,290.50 : x
2. Step 2: Convert to fraction form
   2,285.13/3,153.30 = 1,290.50/x
3. Step 3: Cross multiply
   2,285.13x = 3,153.30 × 1,290.50
4. Step 4: Simplify right side
   2,285.13x = 4,069,317.88
5. Step 5: Solve for x
   x = 4,069,317.88/2,285.13
6. Step 6: Final answer
   x = 1,780.78