Finding the Third Proportional to 66,577.50 and 89,979.75

Step by Step Solution

1. Step 1: Write the proportion equation
   66,577.50 : 89,979.75 = 89,979.75 : x
2. Step 2: Convert to fraction form
   66,577.50/89,979.75 = 89,979.75/x
3. Step 3: Cross multiply
   66,577.50x = 89,979.75 × 89,979.75
4. Step 4: Simplify right side
   66,577.50x = 8,096,355,410.06
5. Step 5: Solve for x
   x = 8,096,355,410.06/66,577.50
6. Step 6: Final answer
   x = 121,607.98