Finding the Third Proportional to 20,120 and 31,139

Step by Step Solution

1. Step 1: Write the proportion equation
   20,120 : 31,139 = 31,139 : x
2. Step 2: Convert to fraction form
   20,120/31,139 = 31,139/x
3. Step 3: Cross multiply
   20,120x = 31,139 × 31,139
4. Step 4: Simplify right side
   20,120x = 969,637,321
5. Step 5: Solve for x
   x = 969,637,321/20,120
6. Step 6: Final answer
   x = 48,192.71