Finding the Fourth Proportional to 1,339.21, 1,848.18 and 780.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,339.21 : 1,848.18 = 780.04 : x
2. Step 2: Convert to fraction form
   1,339.21/1,848.18 = 780.04/x
3. Step 3: Cross multiply
   1,339.21x = 1,848.18 × 780.04
4. Step 4: Simplify right side
   1,339.21x = 1,441,654.33
5. Step 5: Solve for x
   x = 1,441,654.33/1,339.21
6. Step 6: Final answer
   x = 1,076.50