Finding the Third Proportional to 311.25 and 343.50

Step by Step Solution

1. Step 1: Write the proportion equation
   311.25 : 343.50 = 343.50 : x
2. Step 2: Convert to fraction form
   311.25/343.50 = 343.50/x
3. Step 3: Cross multiply
   311.25x = 343.50 × 343.50
4. Step 4: Simplify right side
   311.25x = 117,992.25
5. Step 5: Solve for x
   x = 117,992.25/311.25
6. Step 6: Final answer
   x = 379.09