Finding the Third Proportional to 21,086 and 42,778

Step by Step Solution

1. Step 1: Write the proportion equation
   21,086 : 42,778 = 42,778 : x
2. Step 2: Convert to fraction form
   21,086/42,778 = 42,778/x
3. Step 3: Cross multiply
   21,086x = 42,778 × 42,778
4. Step 4: Simplify right side
   21,086x = 1,829,957,284
5. Step 5: Solve for x
   x = 1,829,957,284/21,086
6. Step 6: Final answer
   x = 86,785.42