Finding the Third Proportional to 12,387.30 and 21,870

Step by Step Solution

1. Step 1: Write the proportion equation
   12,387.30 : 21,870 = 21,870 : x
2. Step 2: Convert to fraction form
   12,387.30/21,870 = 21,870/x
3. Step 3: Cross multiply
   12,387.30x = 21,870 × 21,870
4. Step 4: Simplify right side
   12,387.30x = 478,296,900
5. Step 5: Solve for x
   x = 478,296,900/12,387.30
6. Step 6: Final answer
   x = 38,611.86