Finding the Fourth Proportional to 2,691.60, 4,040.40 and 1,392.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,691.60 : 4,040.40 = 1,392.72 : x
2. Step 2: Convert to fraction form
   2,691.60/4,040.40 = 1,392.72/x
3. Step 3: Cross multiply
   2,691.60x = 4,040.40 × 1,392.72
4. Step 4: Simplify right side
   2,691.60x = 5,627,145.89
5. Step 5: Solve for x
   x = 5,627,145.89/2,691.60
6. Step 6: Final answer
   x = 2,090.63