Finding the Fourth Proportional to 1,385.25, 1,911.92 and 825.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.25 : 1,911.92 = 825.81 : x
2. Step 2: Convert to fraction form
   1,385.25/1,911.92 = 825.81/x
3. Step 3: Cross multiply
   1,385.25x = 1,911.92 × 825.81
4. Step 4: Simplify right side
   1,385.25x = 1,578,878.53
5. Step 5: Solve for x
   x = 1,578,878.53/1,385.25
6. Step 6: Final answer
   x = 1,139.78