Finding the Fourth Proportional to 1,256.59, 1,732.72 and 858.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,256.59 : 1,732.72 = 858.30 : x
2. Step 2: Convert to fraction form
   1,256.59/1,732.72 = 858.30/x
3. Step 3: Cross multiply
   1,256.59x = 1,732.72 × 858.30
4. Step 4: Simplify right side
   1,256.59x = 1,487,193.58
5. Step 5: Solve for x
   x = 1,487,193.58/1,256.59
6. Step 6: Final answer
   x = 1,183.52