Finding the Fourth Proportional to 1,019.06, 1,405.06 and 861.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.06 : 1,405.06 = 861.42 : x
2. Step 2: Convert to fraction form
   1,019.06/1,405.06 = 861.42/x
3. Step 3: Cross multiply
   1,019.06x = 1,405.06 × 861.42
4. Step 4: Simplify right side
   1,019.06x = 1,210,346.79
5. Step 5: Solve for x
   x = 1,210,346.79/1,019.06
6. Step 6: Final answer
   x = 1,187.71