Finding the Third Proportional to 18,540 and 39,978

Step by Step Solution

1. Step 1: Write the proportion equation
   18,540 : 39,978 = 39,978 : x
2. Step 2: Convert to fraction form
   18,540/39,978 = 39,978/x
3. Step 3: Cross multiply
   18,540x = 39,978 × 39,978
4. Step 4: Simplify right side
   18,540x = 1,598,240,484
5. Step 5: Solve for x
   x = 1,598,240,484/18,540
6. Step 6: Final answer
   x = 86,204.99