Finding the Fourth Proportional to 1,384.98, 1,911.33 and 825.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,384.98 : 1,911.33 = 825.78 : x
2. Step 2: Convert to fraction form
   1,384.98/1,911.33 = 825.78/x
3. Step 3: Cross multiply
   1,384.98x = 1,911.33 × 825.78
4. Step 4: Simplify right side
   1,384.98x = 1,578,338.09
5. Step 5: Solve for x
   x = 1,578,338.09/1,384.98
6. Step 6: Final answer
   x = 1,139.61