Finding the Third Proportional to 66,100.50 and 128,880

Step by Step Solution

1. Step 1: Write the proportion equation
   66,100.50 : 128,880 = 128,880 : x
2. Step 2: Convert to fraction form
   66,100.50/128,880 = 128,880/x
3. Step 3: Cross multiply
   66,100.50x = 128,880 × 128,880
4. Step 4: Simplify right side
   66,100.50x = 16,610,054,400
5. Step 5: Solve for x
   x = 16,610,054,400/66,100.50
6. Step 6: Final answer
   x = 251,284.85