Finding the Fourth Proportional to 2,659.72, 3,989.60 and 928.34

Step by Step Solution

1. Step 1: Write the proportion equation
   2,659.72 : 3,989.60 = 928.34 : x
2. Step 2: Convert to fraction form
   2,659.72/3,989.60 = 928.34/x
3. Step 3: Cross multiply
   2,659.72x = 3,989.60 × 928.34
4. Step 4: Simplify right side
   2,659.72x = 3,703,705.26
5. Step 5: Solve for x
   x = 3,703,705.26/2,659.72
6. Step 6: Final answer
   x = 1,392.52