Finding the Third Proportional to 12,939.75 and 20,070.28

Step by Step Solution

1. Step 1: Write the proportion equation
   12,939.75 : 20,070.28 = 20,070.28 : x
2. Step 2: Convert to fraction form
   12,939.75/20,070.28 = 20,070.28/x
3. Step 3: Cross multiply
   12,939.75x = 20,070.28 × 20,070.28
4. Step 4: Simplify right side
   12,939.75x = 402,816,189.45
5. Step 5: Solve for x
   x = 402,816,189.45/12,939.75
6. Step 6: Final answer
   x = 31,130.14