Finding the Fourth Proportional to 2,659.57, 3,991.18 and 928.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,659.57 : 3,991.18 = 928.20 : x
2. Step 2: Convert to fraction form
   2,659.57/3,991.18 = 928.20/x
3. Step 3: Cross multiply
   2,659.57x = 3,991.18 × 928.20
4. Step 4: Simplify right side
   2,659.57x = 3,704,593.32
5. Step 5: Solve for x
   x = 3,704,593.32/2,659.57
6. Step 6: Final answer
   x = 1,392.93