Finding the Fourth Proportional to 2,660.46, 3,989.61 and 928.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,660.46 : 3,989.61 = 928.50 : x
2. Step 2: Convert to fraction form
   2,660.46/3,989.61 = 928.50/x
3. Step 3: Cross multiply
   2,660.46x = 3,989.61 × 928.50
4. Step 4: Simplify right side
   2,660.46x = 3,704,352.89
5. Step 5: Solve for x
   x = 3,704,352.89/2,660.46
6. Step 6: Final answer
   x = 1,392.37