Finding the Third Proportional to 21,480.19 and 39,907.69

Step by Step Solution

1. Step 1: Write the proportion equation
   21,480.19 : 39,907.69 = 39,907.69 : x
2. Step 2: Convert to fraction form
   21,480.19/39,907.69 = 39,907.69/x
3. Step 3: Cross multiply
   21,480.19x = 39,907.69 × 39,907.69
4. Step 4: Simplify right side
   21,480.19x = 1,592,623,521.60
5. Step 5: Solve for x
   x = 1,592,623,521.60/21,480.19
6. Step 6: Final answer
   x = 74,143.84