Finding the Third Proportional to 12,128 and 19,172

Step by Step Solution

1. Step 1: Write the proportion equation
   12,128 : 19,172 = 19,172 : x
2. Step 2: Convert to fraction form
   12,128/19,172 = 19,172/x
3. Step 3: Cross multiply
   12,128x = 19,172 × 19,172
4. Step 4: Simplify right side
   12,128x = 367,565,584
5. Step 5: Solve for x
   x = 367,565,584/12,128
6. Step 6: Final answer
   x = 30,307.19