Finding the Fourth Proportional to 2,312.78, 3,467.79 and 1,387.76

Step by Step Solution

1. Step 1: Write the proportion equation
   2,312.78 : 3,467.79 = 1,387.76 : x
2. Step 2: Convert to fraction form
   2,312.78/3,467.79 = 1,387.76/x
3. Step 3: Cross multiply
   2,312.78x = 3,467.79 × 1,387.76
4. Step 4: Simplify right side
   2,312.78x = 4,812,442.91
5. Step 5: Solve for x
   x = 4,812,442.91/2,312.78
6. Step 6: Final answer
   x = 2,080.81