Finding the Fourth Proportional to 1,339.38, 1,848.31 and 780.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,339.38 : 1,848.31 = 780.07 : x
2. Step 2: Convert to fraction form
   1,339.38/1,848.31 = 780.07/x
3. Step 3: Cross multiply
   1,339.38x = 1,848.31 × 780.07
4. Step 4: Simplify right side
   1,339.38x = 1,441,811.18
5. Step 5: Solve for x
   x = 1,441,811.18/1,339.38
6. Step 6: Final answer
   x = 1,076.48