Finding the Fourth Proportional to 2,558.78, 3,838.86 and 1,388.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,558.78 : 3,838.86 = 1,388.50 : x
2. Step 2: Convert to fraction form
   2,558.78/3,838.86 = 1,388.50/x
3. Step 3: Cross multiply
   2,558.78x = 3,838.86 × 1,388.50
4. Step 4: Simplify right side
   2,558.78x = 5,330,257.11
5. Step 5: Solve for x
   x = 5,330,257.11/2,558.78
6. Step 6: Final answer
   x = 2,083.12