Finding the Fourth Proportional to 1,920.31, 2,650.17 and 1,081.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,920.31 : 2,650.17 = 1,081.15 : x
2. Step 2: Convert to fraction form
   1,920.31/2,650.17 = 1,081.15/x
3. Step 3: Cross multiply
   1,920.31x = 2,650.17 × 1,081.15
4. Step 4: Simplify right side
   1,920.31x = 2,865,231.30
5. Step 5: Solve for x
   x = 2,865,231.30/1,920.31
6. Step 6: Final answer
   x = 1,492.07