Finding the Third Proportional to 66,439.50 and 89,506.50

Step by Step Solution

1. Step 1: Write the proportion equation
   66,439.50 : 89,506.50 = 89,506.50 : x
2. Step 2: Convert to fraction form
   66,439.50/89,506.50 = 89,506.50/x
3. Step 3: Cross multiply
   66,439.50x = 89,506.50 × 89,506.50
4. Step 4: Simplify right side
   66,439.50x = 8,011,413,542.25
5. Step 5: Solve for x
   x = 8,011,413,542.25/66,439.50
6. Step 6: Final answer
   x = 120,582.09