Finding the Third Proportional to 66,420 and 98,689.50

Step by Step Solution

1. Step 1: Write the proportion equation
   66,420 : 98,689.50 = 98,689.50 : x
2. Step 2: Convert to fraction form
   66,420/98,689.50 = 98,689.50/x
3. Step 3: Cross multiply
   66,420x = 98,689.50 × 98,689.50
4. Step 4: Simplify right side
   66,420x = 9,739,617,410.25
5. Step 5: Solve for x
   x = 9,739,617,410.25/66,420
6. Step 6: Final answer
   x = 146,636.82