Finding the Fourth Proportional to 1,369.83, 1,890.37 and 780.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,369.83 : 1,890.37 = 780.37 : x
2. Step 2: Convert to fraction form
   1,369.83/1,890.37 = 780.37/x
3. Step 3: Cross multiply
   1,369.83x = 1,890.37 × 780.37
4. Step 4: Simplify right side
   1,369.83x = 1,475,184.29
5. Step 5: Solve for x
   x = 1,475,184.29/1,369.83
6. Step 6: Final answer
   x = 1,076.91