Finding the Third Proportional to 391.88 and 928.31

Step by Step Solution

1. Step 1: Write the proportion equation
   391.88 : 928.31 = 928.31 : x
2. Step 2: Convert to fraction form
   391.88/928.31 = 928.31/x
3. Step 3: Cross multiply
   391.88x = 928.31 × 928.31
4. Step 4: Simplify right side
   391.88x = 861,764.10
5. Step 5: Solve for x
   x = 861,764.10/391.88
6. Step 6: Final answer
   x = 2,199.08