Finding the Third Proportional to 19,780 and 31,309

Step by Step Solution

1. Step 1: Write the proportion equation
   19,780 : 31,309 = 31,309 : x
2. Step 2: Convert to fraction form
   19,780/31,309 = 31,309/x
3. Step 3: Cross multiply
   19,780x = 31,309 × 31,309
4. Step 4: Simplify right side
   19,780x = 980,253,481
5. Step 5: Solve for x
   x = 980,253,481/19,780
6. Step 6: Final answer
   x = 49,557.81