Finding the Fourth Proportional to 1,369.92, 1,890.27 and 780.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,369.92 : 1,890.27 = 780.47 : x
2. Step 2: Convert to fraction form
   1,369.92/1,890.27 = 780.47/x
3. Step 3: Cross multiply
   1,369.92x = 1,890.27 × 780.47
4. Step 4: Simplify right side
   1,369.92x = 1,475,299.03
5. Step 5: Solve for x
   x = 1,475,299.03/1,369.92
6. Step 6: Final answer
   x = 1,076.92