Finding the Fourth Proportional to 1,340.08, 1,849.61 and 780.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,340.08 : 1,849.61 = 780.57 : x
2. Step 2: Convert to fraction form
   1,340.08/1,849.61 = 780.57/x
3. Step 3: Cross multiply
   1,340.08x = 1,849.61 × 780.57
4. Step 4: Simplify right side
   1,340.08x = 1,443,752.03
5. Step 5: Solve for x
   x = 1,443,752.03/1,340.08
6. Step 6: Final answer
   x = 1,077.36