Finding the Third Proportional to 15,856 and 21,340

Step by Step Solution

1. Step 1: Write the proportion equation
   15,856 : 21,340 = 21,340 : x
2. Step 2: Convert to fraction form
   15,856/21,340 = 21,340/x
3. Step 3: Cross multiply
   15,856x = 21,340 × 21,340
4. Step 4: Simplify right side
   15,856x = 455,395,600
5. Step 5: Solve for x
   x = 455,395,600/15,856
6. Step 6: Final answer
   x = 28,720.71