Finding the Third Proportional to 86.38 and 190.63

Step by Step Solution

1. Step 1: Write the proportion equation
   86.38 : 190.63 = 190.63 : x
2. Step 2: Convert to fraction form
   86.38/190.63 = 190.63/x
3. Step 3: Cross multiply
   86.38x = 190.63 × 190.63
4. Step 4: Simplify right side
   86.38x = 36,337.89
5. Step 5: Solve for x
   x = 36,337.89/86.38
6. Step 6: Final answer
   x = 420.70