Finding the Fourth Proportional to 1,356.89, 1,872.64 and 825.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,356.89 : 1,872.64 = 825.81 : x
2. Step 2: Convert to fraction form
   1,356.89/1,872.64 = 825.81/x
3. Step 3: Cross multiply
   1,356.89x = 1,872.64 × 825.81
4. Step 4: Simplify right side
   1,356.89x = 1,546,435.48
5. Step 5: Solve for x
   x = 1,546,435.48/1,356.89
6. Step 6: Final answer
   x = 1,139.70