Finding the Fourth Proportional to 2,387.40, 3,294.60 and 1,392.75

Step by Step Solution

1. Step 1: Write the proportion equation
   2,387.40 : 3,294.60 = 1,392.75 : x
2. Step 2: Convert to fraction form
   2,387.40/3,294.60 = 1,392.75/x
3. Step 3: Cross multiply
   2,387.40x = 3,294.60 × 1,392.75
4. Step 4: Simplify right side
   2,387.40x = 4,588,554.15
5. Step 5: Solve for x
   x = 4,588,554.15/2,387.40
6. Step 6: Final answer
   x = 1,921.99