Finding the Fourth Proportional to 1,002.78, 1,383.81 and 560.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,002.78 : 1,383.81 = 560.72 : x
2. Step 2: Convert to fraction form
   1,002.78/1,383.81 = 560.72/x
3. Step 3: Cross multiply
   1,002.78x = 1,383.81 × 560.72
4. Step 4: Simplify right side
   1,002.78x = 775,929.94
5. Step 5: Solve for x
   x = 775,929.94/1,002.78
6. Step 6: Final answer
   x = 773.78