Finding the Fourth Proportional to 2,078.61, 3,115.31 and 1,038.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,078.61 : 3,115.31 = 1,038.90 : x
2. Step 2: Convert to fraction form
   2,078.61/3,115.31 = 1,038.90/x
3. Step 3: Cross multiply
   2,078.61x = 3,115.31 × 1,038.90
4. Step 4: Simplify right side
   2,078.61x = 3,236,495.56
5. Step 5: Solve for x
   x = 3,236,495.56/2,078.61
6. Step 6: Final answer
   x = 1,557.05