Finding the Fourth Proportional to 1,687.29, 2,530.29 and 864.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,687.29 : 2,530.29 = 864.72 : x
2. Step 2: Convert to fraction form
   1,687.29/2,530.29 = 864.72/x
3. Step 3: Cross multiply
   1,687.29x = 2,530.29 × 864.72
4. Step 4: Simplify right side
   1,687.29x = 2,187,992.37
5. Step 5: Solve for x
   x = 2,187,992.37/1,687.29
6. Step 6: Final answer
   x = 1,296.75