Finding the Third Proportional to 12,990 and 17,352

Step by Step Solution

1. Step 1: Write the proportion equation
   12,990 : 17,352 = 17,352 : x
2. Step 2: Convert to fraction form
   12,990/17,352 = 17,352/x
3. Step 3: Cross multiply
   12,990x = 17,352 × 17,352
4. Step 4: Simplify right side
   12,990x = 301,091,904
5. Step 5: Solve for x
   x = 301,091,904/12,990
6. Step 6: Final answer
   x = 23,178.75