Finding the Third Proportional to 12,957 and 21,210

Step by Step Solution

1. Step 1: Write the proportion equation
   12,957 : 21,210 = 21,210 : x
2. Step 2: Convert to fraction form
   12,957/21,210 = 21,210/x
3. Step 3: Cross multiply
   12,957x = 21,210 × 21,210
4. Step 4: Simplify right side
   12,957x = 449,864,100
5. Step 5: Solve for x
   x = 449,864,100/12,957
6. Step 6: Final answer
   x = 34,719.77