Finding the Fourth Proportional to 1,379.12, 1,902.72 and 781.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.12 : 1,902.72 = 781.52 : x
2. Step 2: Convert to fraction form
   1,379.12/1,902.72 = 781.52/x
3. Step 3: Cross multiply
   1,379.12x = 1,902.72 × 781.52
4. Step 4: Simplify right side
   1,379.12x = 1,487,013.73
5. Step 5: Solve for x
   x = 1,487,013.73/1,379.12
6. Step 6: Final answer
   x = 1,078.23