Finding the Fourth Proportional to 1,116.81, 1,672.09 and 842.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.81 : 1,672.09 = 842.07 : x
2. Step 2: Convert to fraction form
   1,116.81/1,672.09 = 842.07/x
3. Step 3: Cross multiply
   1,116.81x = 1,672.09 × 842.07
4. Step 4: Simplify right side
   1,116.81x = 1,408,016.83
5. Step 5: Solve for x
   x = 1,408,016.83/1,116.81
6. Step 6: Final answer
   x = 1,260.75