Finding the Third Proportional to 7,878 and 12,895

Step by Step Solution

1. Step 1: Write the proportion equation
   7,878 : 12,895 = 12,895 : x
2. Step 2: Convert to fraction form
   7,878/12,895 = 12,895/x
3. Step 3: Cross multiply
   7,878x = 12,895 × 12,895
4. Step 4: Simplify right side
   7,878x = 166,281,025
5. Step 5: Solve for x
   x = 166,281,025/7,878
6. Step 6: Final answer
   x = 21,107.01