Finding the Third Proportional to 31,128.25 and 66,630.50

Step by Step Solution

1. Step 1: Write the proportion equation
   31,128.25 : 66,630.50 = 66,630.50 : x
2. Step 2: Convert to fraction form
   31,128.25/66,630.50 = 66,630.50/x
3. Step 3: Cross multiply
   31,128.25x = 66,630.50 × 66,630.50
4. Step 4: Simplify right side
   31,128.25x = 4,439,623,530.25
5. Step 5: Solve for x
   x = 4,439,623,530.25/31,128.25
6. Step 6: Final answer
   x = 142,623.61