Finding the Third Proportional to 12,990 and 20,152

Step by Step Solution

1. Step 1: Write the proportion equation
   12,990 : 20,152 = 20,152 : x
2. Step 2: Convert to fraction form
   12,990/20,152 = 20,152/x
3. Step 3: Cross multiply
   12,990x = 20,152 × 20,152
4. Step 4: Simplify right side
   12,990x = 406,103,104
5. Step 5: Solve for x
   x = 406,103,104/12,990
6. Step 6: Final answer
   x = 31,262.75