Finding the Fourth Proportional to 2,016.78, 3,025.80 and 920.25

Step by Step Solution

1. Step 1: Write the proportion equation
   2,016.78 : 3,025.80 = 920.25 : x
2. Step 2: Convert to fraction form
   2,016.78/3,025.80 = 920.25/x
3. Step 3: Cross multiply
   2,016.78x = 3,025.80 × 920.25
4. Step 4: Simplify right side
   2,016.78x = 2,784,492.45
5. Step 5: Solve for x
   x = 2,784,492.45/2,016.78
6. Step 6: Final answer
   x = 1,380.66