Finding the Third Proportional to 12,912 and 21,298

Step by Step Solution

1. Step 1: Write the proportion equation
   12,912 : 21,298 = 21,298 : x
2. Step 2: Convert to fraction form
   12,912/21,298 = 21,298/x
3. Step 3: Cross multiply
   12,912x = 21,298 × 21,298
4. Step 4: Simplify right side
   12,912x = 453,604,804
5. Step 5: Solve for x
   x = 453,604,804/12,912
6. Step 6: Final answer
   x = 35,130.48