Finding the Third Proportional to 9,978 and 13,815

Step by Step Solution

1. Step 1: Write the proportion equation
   9,978 : 13,815 = 13,815 : x
2. Step 2: Convert to fraction form
   9,978/13,815 = 13,815/x
3. Step 3: Cross multiply
   9,978x = 13,815 × 13,815
4. Step 4: Simplify right side
   9,978x = 190,854,225
5. Step 5: Solve for x
   x = 190,854,225/9,978
6. Step 6: Final answer
   x = 19,127.50