Finding the Fourth Proportional to 3,320.11, 4,978.95 and 1,128.25

Step by Step Solution

1. Step 1: Write the proportion equation
   3,320.11 : 4,978.95 = 1,128.25 : x
2. Step 2: Convert to fraction form
   3,320.11/4,978.95 = 1,128.25/x
3. Step 3: Cross multiply
   3,320.11x = 4,978.95 × 1,128.25
4. Step 4: Simplify right side
   3,320.11x = 5,617,500.34
5. Step 5: Solve for x
   x = 5,617,500.34/3,320.11
6. Step 6: Final answer
   x = 1,691.96