Finding the Third Proportional to 66,609.50 and 99,711.75

Step by Step Solution

1. Step 1: Write the proportion equation
   66,609.50 : 99,711.75 = 99,711.75 : x
2. Step 2: Convert to fraction form
   66,609.50/99,711.75 = 99,711.75/x
3. Step 3: Cross multiply
   66,609.50x = 99,711.75 × 99,711.75
4. Step 4: Simplify right side
   66,609.50x = 9,942,433,088.06
5. Step 5: Solve for x
   x = 9,942,433,088.06/66,609.50
6. Step 6: Final answer
   x = 149,264.49