Finding the Fourth Proportional to 2,687.98, 3,700.31 and 2,312.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,687.98 : 3,700.31 = 2,312.78 : x
2. Step 2: Convert to fraction form
   2,687.98/3,700.31 = 2,312.78/x
3. Step 3: Cross multiply
   2,687.98x = 3,700.31 × 2,312.78
4. Step 4: Simplify right side
   2,687.98x = 8,558,002.96
5. Step 5: Solve for x
   x = 8,558,002.96/2,687.98
6. Step 6: Final answer
   x = 3,183.80