Finding the Fourth Proportional to 1,340.16, 1,849.18 and 780.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,340.16 : 1,849.18 = 780.60 : x
2. Step 2: Convert to fraction form
   1,340.16/1,849.18 = 780.60/x
3. Step 3: Cross multiply
   1,340.16x = 1,849.18 × 780.60
4. Step 4: Simplify right side
   1,340.16x = 1,443,469.91
5. Step 5: Solve for x
   x = 1,443,469.91/1,340.16
6. Step 6: Final answer
   x = 1,077.09