Finding the Third Proportional to 13,156.31 and 20,221.31

Step by Step Solution

1. Step 1: Write the proportion equation
   13,156.31 : 20,221.31 = 20,221.31 : x
2. Step 2: Convert to fraction form
   13,156.31/20,221.31 = 20,221.31/x
3. Step 3: Cross multiply
   13,156.31x = 20,221.31 × 20,221.31
4. Step 4: Simplify right side
   13,156.31x = 408,901,479.22
5. Step 5: Solve for x
   x = 408,901,479.22/13,156.31
6. Step 6: Final answer
   x = 31,080.25