Finding the Fourth Proportional to 1,256.72, 1,734.89 and 860.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,256.72 : 1,734.89 = 860.46 : x
2. Step 2: Convert to fraction form
   1,256.72/1,734.89 = 860.46/x
3. Step 3: Cross multiply
   1,256.72x = 1,734.89 × 860.46
4. Step 4: Simplify right side
   1,256.72x = 1,492,792.64
5. Step 5: Solve for x
   x = 1,492,792.64/1,256.72
6. Step 6: Final answer
   x = 1,187.85