Finding the Fourth Proportional to 1,281.78, 1,768.59 and 784.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,281.78 : 1,768.59 = 784.53 : x
2. Step 2: Convert to fraction form
   1,281.78/1,768.59 = 784.53/x
3. Step 3: Cross multiply
   1,281.78x = 1,768.59 × 784.53
4. Step 4: Simplify right side
   1,281.78x = 1,387,511.91
5. Step 5: Solve for x
   x = 1,387,511.91/1,281.78
6. Step 6: Final answer
   x = 1,082.49