Finding the Third Proportional to 99.56 and 212.63

Step by Step Solution

1. Step 1: Write the proportion equation
   99.56 : 212.63 = 212.63 : x
2. Step 2: Convert to fraction form
   99.56/212.63 = 212.63/x
3. Step 3: Cross multiply
   99.56x = 212.63 × 212.63
4. Step 4: Simplify right side
   99.56x = 45,209.39
5. Step 5: Solve for x
   x = 45,209.39/99.56
6. Step 6: Final answer
   x = 454.08