Finding the Fourth Proportional to 1,385.21, 1,911.25 and 825.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.21 : 1,911.25 = 825.32 : x
2. Step 2: Convert to fraction form
   1,385.21/1,911.25 = 825.32/x
3. Step 3: Cross multiply
   1,385.21x = 1,911.25 × 825.32
4. Step 4: Simplify right side
   1,385.21x = 1,577,392.85
5. Step 5: Solve for x
   x = 1,577,392.85/1,385.21
6. Step 6: Final answer
   x = 1,138.74