Finding the Fourth Proportional to 1,385.59, 1,912.12 and 825.95

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.59 : 1,912.12 = 825.95 : x
2. Step 2: Convert to fraction form
   1,385.59/1,912.12 = 825.95/x
3. Step 3: Cross multiply
   1,385.59x = 1,912.12 × 825.95
4. Step 4: Simplify right side
   1,385.59x = 1,579,315.51
5. Step 5: Solve for x
   x = 1,579,315.51/1,385.59
6. Step 6: Final answer
   x = 1,139.81