Finding the Fourth Proportional to 1,686.56, 2,530.74 and 864.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,686.56 : 2,530.74 = 864.61 : x
2. Step 2: Convert to fraction form
   1,686.56/2,530.74 = 864.61/x
3. Step 3: Cross multiply
   1,686.56x = 2,530.74 × 864.61
4. Step 4: Simplify right side
   1,686.56x = 2,188,100.03
5. Step 5: Solve for x
   x = 2,188,100.03/1,686.56
6. Step 6: Final answer
   x = 1,297.38