Finding the Third Proportional to 12,973.50 and 20,128.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,973.50 : 20,128.50 = 20,128.50 : x
2. Step 2: Convert to fraction form
   12,973.50/20,128.50 = 20,128.50/x
3. Step 3: Cross multiply
   12,973.50x = 20,128.50 × 20,128.50
4. Step 4: Simplify right side
   12,973.50x = 405,156,512.25
5. Step 5: Solve for x
   x = 405,156,512.25/12,973.50
6. Step 6: Final answer
   x = 31,229.55