Finding the Fourth Proportional to 2,149.47, 3,222.63 and 687.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,149.47 : 3,222.63 = 687.78 : x
2. Step 2: Convert to fraction form
   2,149.47/3,222.63 = 687.78/x
3. Step 3: Cross multiply
   2,149.47x = 3,222.63 × 687.78
4. Step 4: Simplify right side
   2,149.47x = 2,216,460.46
5. Step 5: Solve for x
   x = 2,216,460.46/2,149.47
6. Step 6: Final answer
   x = 1,031.17