Finding the Third Proportional to 90.65 and 198.39

Step by Step Solution

1. Step 1: Write the proportion equation
   90.65 : 198.39 = 198.39 : x
2. Step 2: Convert to fraction form
   90.65/198.39 = 198.39/x
3. Step 3: Cross multiply
   90.65x = 198.39 × 198.39
4. Step 4: Simplify right side
   90.65x = 39,357.29
5. Step 5: Solve for x
   x = 39,357.29/90.65
6. Step 6: Final answer
   x = 434.17