Finding the Fourth Proportional to 1,371.18, 1,892.24 and 781.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,371.18 : 1,892.24 = 781.72 : x
2. Step 2: Convert to fraction form
   1,371.18/1,892.24 = 781.72/x
3. Step 3: Cross multiply
   1,371.18x = 1,892.24 × 781.72
4. Step 4: Simplify right side
   1,371.18x = 1,479,201.85
5. Step 5: Solve for x
   x = 1,479,201.85/1,371.18
6. Step 6: Final answer
   x = 1,078.78