Finding the Third Proportional to 165.50 and 319.50

Step by Step Solution

1. Step 1: Write the proportion equation
   165.50 : 319.50 = 319.50 : x
2. Step 2: Convert to fraction form
   165.50/319.50 = 319.50/x
3. Step 3: Cross multiply
   165.50x = 319.50 × 319.50
4. Step 4: Simplify right side
   165.50x = 102,080.25
5. Step 5: Solve for x
   x = 102,080.25/165.50
6. Step 6: Final answer
   x = 616.80