Finding the Fourth Proportional to 1,205.05, 1,662.91 and 681.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,205.05 : 1,662.91 = 681.05 : x
2. Step 2: Convert to fraction form
   1,205.05/1,662.91 = 681.05/x
3. Step 3: Cross multiply
   1,205.05x = 1,662.91 × 681.05
4. Step 4: Simplify right side
   1,205.05x = 1,132,521.45
5. Step 5: Solve for x
   x = 1,132,521.45/1,205.05
6. Step 6: Final answer
   x = 939.81