Finding the Third Proportional to 9,978.19 and 21,839.63

Step by Step Solution

1. Step 1: Write the proportion equation
   9,978.19 : 21,839.63 = 21,839.63 : x
2. Step 2: Convert to fraction form
   9,978.19/21,839.63 = 21,839.63/x
3. Step 3: Cross multiply
   9,978.19x = 21,839.63 × 21,839.63
4. Step 4: Simplify right side
   9,978.19x = 476,969,220.14
5. Step 5: Solve for x
   x = 476,969,220.14/9,978.19
6. Step 6: Final answer
   x = 47,801.19