Finding the Fourth Proportional to 3,320.89, 4,979.90 and 1,128.62

Step by Step Solution

1. Step 1: Write the proportion equation
   3,320.89 : 4,979.90 = 1,128.62 : x
2. Step 2: Convert to fraction form
   3,320.89/4,979.90 = 1,128.62/x
3. Step 3: Cross multiply
   3,320.89x = 4,979.90 × 1,128.62
4. Step 4: Simplify right side
   3,320.89x = 5,620,430.01
5. Step 5: Solve for x
   x = 5,620,430.01/3,320.89
6. Step 6: Final answer
   x = 1,692.45