Finding the Fourth Proportional to 1,395.31, 1,925.12 and 864.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,395.31 : 1,925.12 = 864.58 : x
2. Step 2: Convert to fraction form
   1,395.31/1,925.12 = 864.58/x
3. Step 3: Cross multiply
   1,395.31x = 1,925.12 × 864.58
4. Step 4: Simplify right side
   1,395.31x = 1,664,421.76
5. Step 5: Solve for x
   x = 1,664,421.76/1,395.31
6. Step 6: Final answer
   x = 1,192.87