Finding the Fourth Proportional to 1,384.90, 1,911.19 and 825.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,384.90 : 1,911.19 = 825.47 : x
2. Step 2: Convert to fraction form
   1,384.90/1,911.19 = 825.47/x
3. Step 3: Cross multiply
   1,384.90x = 1,911.19 × 825.47
4. Step 4: Simplify right side
   1,384.90x = 1,577,632.72
5. Step 5: Solve for x
   x = 1,577,632.72/1,384.90
6. Step 6: Final answer
   x = 1,139.17