Finding the Fourth Proportional to 1,016.78, 1,406.86 and 886.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,016.78 : 1,406.86 = 886.06 : x
2. Step 2: Convert to fraction form
   1,016.78/1,406.86 = 886.06/x
3. Step 3: Cross multiply
   1,016.78x = 1,406.86 × 886.06
4. Step 4: Simplify right side
   1,016.78x = 1,246,562.37
5. Step 5: Solve for x
   x = 1,246,562.37/1,016.78
6. Step 6: Final answer
   x = 1,225.99