Finding the Fourth Proportional to 1,384.80, 1,910.93 and 825.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,384.80 : 1,910.93 = 825.31 : x
2. Step 2: Convert to fraction form
   1,384.80/1,910.93 = 825.31/x
3. Step 3: Cross multiply
   1,384.80x = 1,910.93 × 825.31
4. Step 4: Simplify right side
   1,384.80x = 1,577,109.64
5. Step 5: Solve for x
   x = 1,577,109.64/1,384.80
6. Step 6: Final answer
   x = 1,138.87