Finding the Third Proportional to 10,400 and 21,286

Step by Step Solution

1. Step 1: Write the proportion equation
   10,400 : 21,286 = 21,286 : x
2. Step 2: Convert to fraction form
   10,400/21,286 = 21,286/x
3. Step 3: Cross multiply
   10,400x = 21,286 × 21,286
4. Step 4: Simplify right side
   10,400x = 453,093,796
5. Step 5: Solve for x
   x = 453,093,796/10,400
6. Step 6: Final answer
   x = 43,566.71