Finding the Fourth Proportional to 1,016.58, 1,400.85 and 861.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,016.58 : 1,400.85 = 861.06 : x
2. Step 2: Convert to fraction form
   1,016.58/1,400.85 = 861.06/x
3. Step 3: Cross multiply
   1,016.58x = 1,400.85 × 861.06
4. Step 4: Simplify right side
   1,016.58x = 1,206,215.90
5. Step 5: Solve for x
   x = 1,206,215.90/1,016.58
6. Step 6: Final answer
   x = 1,186.54