Finding the Fourth Proportional to 1,385.40, 1,912.06 and 825.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.40 : 1,912.06 = 825.92 : x
2. Step 2: Convert to fraction form
   1,385.40/1,912.06 = 825.92/x
3. Step 3: Cross multiply
   1,385.40x = 1,912.06 × 825.92
4. Step 4: Simplify right side
   1,385.40x = 1,579,208.60
5. Step 5: Solve for x
   x = 1,579,208.60/1,385.40
6. Step 6: Final answer
   x = 1,139.89