Finding the Third Proportional to 12,783 and 21,126

Step by Step Solution

1. Step 1: Write the proportion equation
   12,783 : 21,126 = 21,126 : x
2. Step 2: Convert to fraction form
   12,783/21,126 = 21,126/x
3. Step 3: Cross multiply
   12,783x = 21,126 × 21,126
4. Step 4: Simplify right side
   12,783x = 446,307,876
5. Step 5: Solve for x
   x = 446,307,876/12,783
6. Step 6: Final answer
   x = 34,914.17