Finding the Third Proportional to 455.20 and 699.89

Step by Step Solution

1. Step 1: Write the proportion equation
   455.20 : 699.89 = 699.89 : x
2. Step 2: Convert to fraction form
   455.20/699.89 = 699.89/x
3. Step 3: Cross multiply
   455.20x = 699.89 × 699.89
4. Step 4: Simplify right side
   455.20x = 489,846.89
5. Step 5: Solve for x
   x = 489,846.89/455.20
6. Step 6: Final answer
   x = 1,076.11