Finding the Third Proportional to 66,499.50 and 99,817.50

Step by Step Solution

1. Step 1: Write the proportion equation
   66,499.50 : 99,817.50 = 99,817.50 : x
2. Step 2: Convert to fraction form
   66,499.50/99,817.50 = 99,817.50/x
3. Step 3: Cross multiply
   66,499.50x = 99,817.50 × 99,817.50
4. Step 4: Simplify right side
   66,499.50x = 9,963,533,306.25
5. Step 5: Solve for x
   x = 9,963,533,306.25/66,499.50
6. Step 6: Final answer
   x = 149,828.70