Finding the Fourth Proportional to 1,605.05, 2,406.69 and 865.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,605.05 : 2,406.69 = 865.55 : x
2. Step 2: Convert to fraction form
   1,605.05/2,406.69 = 865.55/x
3. Step 3: Cross multiply
   1,605.05x = 2,406.69 × 865.55
4. Step 4: Simplify right side
   1,605.05x = 2,083,098.50
5. Step 5: Solve for x
   x = 2,083,098.50/1,605.05
6. Step 6: Final answer
   x = 1,297.84