Finding the Fourth Proportional to 1,371.28, 1,892.45 and 781.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,371.28 : 1,892.45 = 781.82 : x
2. Step 2: Convert to fraction form
   1,371.28/1,892.45 = 781.82/x
3. Step 3: Cross multiply
   1,371.28x = 1,892.45 × 781.82
4. Step 4: Simplify right side
   1,371.28x = 1,479,555.26
5. Step 5: Solve for x
   x = 1,479,555.26/1,371.28
6. Step 6: Final answer
   x = 1,078.96