Finding the Third Proportional to 54,578 and 86,788

Step by Step Solution

1. Step 1: Write the proportion equation
   54,578 : 86,788 = 86,788 : x
2. Step 2: Convert to fraction form
   54,578/86,788 = 86,788/x
3. Step 3: Cross multiply
   54,578x = 86,788 × 86,788
4. Step 4: Simplify right side
   54,578x = 7,532,156,944
5. Step 5: Solve for x
   x = 7,532,156,944/54,578
6. Step 6: Final answer
   x = 138,007.20