Finding the Fourth Proportional to 2,569.61, 3,855.28 and 814.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,569.61 : 3,855.28 = 814.90 : x
2. Step 2: Convert to fraction form
   2,569.61/3,855.28 = 814.90/x
3. Step 3: Cross multiply
   2,569.61x = 3,855.28 × 814.90
4. Step 4: Simplify right side
   2,569.61x = 3,141,667.67
5. Step 5: Solve for x
   x = 3,141,667.67/2,569.61
6. Step 6: Final answer
   x = 1,222.62