Finding the Fourth Proportional to 1,278.72, 1,921.54 and 694.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,278.72 : 1,921.54 = 694.10 : x
2. Step 2: Convert to fraction form
   1,278.72/1,921.54 = 694.10/x
3. Step 3: Cross multiply
   1,278.72x = 1,921.54 × 694.10
4. Step 4: Simplify right side
   1,278.72x = 1,333,740.91
5. Step 5: Solve for x
   x = 1,333,740.91/1,278.72
6. Step 6: Final answer
   x = 1,043.03