Finding the Third Proportional to 66,690 and 103,189.50

Step by Step Solution

1. Step 1: Write the proportion equation
   66,690 : 103,189.50 = 103,189.50 : x
2. Step 2: Convert to fraction form
   66,690/103,189.50 = 103,189.50/x
3. Step 3: Cross multiply
   66,690x = 103,189.50 × 103,189.50
4. Step 4: Simplify right side
   66,690x = 10,648,072,910.25
5. Step 5: Solve for x
   x = 10,648,072,910.25/66,690
6. Step 6: Final answer
   x = 159,665.21