Finding the Third Proportional to 152.20 and 313.69

Step by Step Solution

1. Step 1: Write the proportion equation
   152.20 : 313.69 = 313.69 : x
2. Step 2: Convert to fraction form
   152.20/313.69 = 313.69/x
3. Step 3: Cross multiply
   152.20x = 313.69 × 313.69
4. Step 4: Simplify right side
   152.20x = 98,399.85
5. Step 5: Solve for x
   x = 98,399.85/152.20
6. Step 6: Final answer
   x = 646.50