Finding the Fourth Proportional to 2,148.72, 3,223.50 and 687.76

Step by Step Solution

1. Step 1: Write the proportion equation
   2,148.72 : 3,223.50 = 687.76 : x
2. Step 2: Convert to fraction form
   2,148.72/3,223.50 = 687.76/x
3. Step 3: Cross multiply
   2,148.72x = 3,223.50 × 687.76
4. Step 4: Simplify right side
   2,148.72x = 2,216,994.36
5. Step 5: Solve for x
   x = 2,216,994.36/2,148.72
6. Step 6: Final answer
   x = 1,031.77