Finding the Third Proportional to 66,015 and 89,689.50

Step by Step Solution

1. Step 1: Write the proportion equation
   66,015 : 89,689.50 = 89,689.50 : x
2. Step 2: Convert to fraction form
   66,015/89,689.50 = 89,689.50/x
3. Step 3: Cross multiply
   66,015x = 89,689.50 × 89,689.50
4. Step 4: Simplify right side
   66,015x = 8,044,206,410.25
5. Step 5: Solve for x
   x = 8,044,206,410.25/66,015
6. Step 6: Final answer
   x = 121,854.22