Finding the Third Proportional to 7,200 and 12,128

Step by Step Solution

1. Step 1: Write the proportion equation
   7,200 : 12,128 = 12,128 : x
2. Step 2: Convert to fraction form
   7,200/12,128 = 12,128/x
3. Step 3: Cross multiply
   7,200x = 12,128 × 12,128
4. Step 4: Simplify right side
   7,200x = 147,088,384
5. Step 5: Solve for x
   x = 147,088,384/7,200
6. Step 6: Final answer
   x = 20,428.94