Finding the Fourth Proportional to 1,339.73, 1,848.83 and 780.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,339.73 : 1,848.83 = 780.58 : x
2. Step 2: Convert to fraction form
   1,339.73/1,848.83 = 780.58/x
3. Step 3: Cross multiply
   1,339.73x = 1,848.83 × 780.58
4. Step 4: Simplify right side
   1,339.73x = 1,443,155.13
5. Step 5: Solve for x
   x = 1,443,155.13/1,339.73
6. Step 6: Final answer
   x = 1,077.20