Finding the Third Proportional to 9,900 and 20,434.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,900 : 20,434.50 = 20,434.50 : x
2. Step 2: Convert to fraction form
   9,900/20,434.50 = 20,434.50/x
3. Step 3: Cross multiply
   9,900x = 20,434.50 × 20,434.50
4. Step 4: Simplify right side
   9,900x = 417,568,790.25
5. Step 5: Solve for x
   x = 417,568,790.25/9,900
6. Step 6: Final answer
   x = 42,178.67