Finding the Fourth Proportional to 1,392.96, 2,087.58 and 1,245.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.96 : 2,087.58 = 1,245.78 : x
2. Step 2: Convert to fraction form
   1,392.96/2,087.58 = 1,245.78/x
3. Step 3: Cross multiply
   1,392.96x = 2,087.58 × 1,245.78
4. Step 4: Simplify right side
   1,392.96x = 2,600,665.41
5. Step 5: Solve for x
   x = 2,600,665.41/1,392.96
6. Step 6: Final answer
   x = 1,867.01