Finding the Fourth Proportional to 1,225.78, 1,691.49 and 694.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,225.78 : 1,691.49 = 694.72 : x
2. Step 2: Convert to fraction form
   1,225.78/1,691.49 = 694.72/x
3. Step 3: Cross multiply
   1,225.78x = 1,691.49 × 694.72
4. Step 4: Simplify right side
   1,225.78x = 1,175,111.93
5. Step 5: Solve for x
   x = 1,175,111.93/1,225.78
6. Step 6: Final answer
   x = 958.66