Finding the Third Proportional to 8,620 and 19,978

Step by Step Solution

1. Step 1: Write the proportion equation
   8,620 : 19,978 = 19,978 : x
2. Step 2: Convert to fraction form
   8,620/19,978 = 19,978/x
3. Step 3: Cross multiply
   8,620x = 19,978 × 19,978
4. Step 4: Simplify right side
   8,620x = 399,120,484
5. Step 5: Solve for x
   x = 399,120,484/8,620
6. Step 6: Final answer
   x = 46,301.68