Finding the Fourth Proportional to 2,148.78, 3,222.78 and 687.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,148.78 : 3,222.78 = 687.96 : x
2. Step 2: Convert to fraction form
   2,148.78/3,222.78 = 687.96/x
3. Step 3: Cross multiply
   2,148.78x = 3,222.78 × 687.96
4. Step 4: Simplify right side
   2,148.78x = 2,217,143.73
5. Step 5: Solve for x
   x = 2,217,143.73/2,148.78
6. Step 6: Final answer
   x = 1,031.82