Finding the Third Proportional to 8,424 and 13,410

Step by Step Solution

1. Step 1: Write the proportion equation
   8,424 : 13,410 = 13,410 : x
2. Step 2: Convert to fraction form
   8,424/13,410 = 13,410/x
3. Step 3: Cross multiply
   8,424x = 13,410 × 13,410
4. Step 4: Simplify right side
   8,424x = 179,828,100
5. Step 5: Solve for x
   x = 179,828,100/8,424
6. Step 6: Final answer
   x = 21,347.12