Finding the Fourth Proportional to 1,369.97, 1,890.69 and 780.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,369.97 : 1,890.69 = 780.62 : x
2. Step 2: Convert to fraction form
   1,369.97/1,890.69 = 780.62/x
3. Step 3: Cross multiply
   1,369.97x = 1,890.69 × 780.62
4. Step 4: Simplify right side
   1,369.97x = 1,475,910.43
5. Step 5: Solve for x
   x = 1,475,910.43/1,369.97
6. Step 6: Final answer
   x = 1,077.33