Finding the Fourth Proportional to 2,148.76, 3,223.34 and 687.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,148.76 : 3,223.34 = 687.57 : x
2. Step 2: Convert to fraction form
   2,148.76/3,223.34 = 687.57/x
3. Step 3: Cross multiply
   2,148.76x = 3,223.34 × 687.57
4. Step 4: Simplify right side
   2,148.76x = 2,216,271.88
5. Step 5: Solve for x
   x = 2,216,271.88/2,148.76
6. Step 6: Final answer
   x = 1,031.42