Finding the Fourth Proportional to 2,148.89, 3,223.53 and 687.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,148.89 : 3,223.53 = 687.69 : x
2. Step 2: Convert to fraction form
   2,148.89/3,223.53 = 687.69/x
3. Step 3: Cross multiply
   2,148.89x = 3,223.53 × 687.69
4. Step 4: Simplify right side
   2,148.89x = 2,216,789.35
5. Step 5: Solve for x
   x = 2,216,789.35/2,148.89
6. Step 6: Final answer
   x = 1,031.60