Finding the Third Proportional to 90.29 and 212.86

Step by Step Solution

1. Step 1: Write the proportion equation
   90.29 : 212.86 = 212.86 : x
2. Step 2: Convert to fraction form
   90.29/212.86 = 212.86/x
3. Step 3: Cross multiply
   90.29x = 212.86 × 212.86
4. Step 4: Simplify right side
   90.29x = 45,310.36
5. Step 5: Solve for x
   x = 45,310.36/90.29
6. Step 6: Final answer
   x = 501.81