Finding the Fourth Proportional to 2,158.78, 3,234.02 and 1,231.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,158.78 : 3,234.02 = 1,231.60 : x
2. Step 2: Convert to fraction form
   2,158.78/3,234.02 = 1,231.60/x
3. Step 3: Cross multiply
   2,158.78x = 3,234.02 × 1,231.60
4. Step 4: Simplify right side
   2,158.78x = 3,983,002.86
5. Step 5: Solve for x
   x = 3,983,002.86/2,158.78
6. Step 6: Final answer
   x = 1,845.03