Finding the Third Proportional to 4,842 and 9,978

Step by Step Solution

1. Step 1: Write the proportion equation
   4,842 : 9,978 = 9,978 : x
2. Step 2: Convert to fraction form
   4,842/9,978 = 9,978/x
3. Step 3: Cross multiply
   4,842x = 9,978 × 9,978
4. Step 4: Simplify right side
   4,842x = 99,560,484
5. Step 5: Solve for x
   x = 99,560,484/4,842
6. Step 6: Final answer
   x = 20,561.85