Finding the Fourth Proportional to 2,652.28, 3,978.69 and 920.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,652.28 : 3,978.69 = 920.50 : x
2. Step 2: Convert to fraction form
   2,652.28/3,978.69 = 920.50/x
3. Step 3: Cross multiply
   2,652.28x = 3,978.69 × 920.50
4. Step 4: Simplify right side
   2,652.28x = 3,662,384.15
5. Step 5: Solve for x
   x = 3,662,384.15/2,652.28
6. Step 6: Final answer
   x = 1,380.84