Finding the Fourth Proportional to 21,978.72, 30,330.63 and 11,907.23

Step by Step Solution

1. Step 1: Write the proportion equation
   21,978.72 : 30,330.63 = 11,907.23 : x
2. Step 2: Convert to fraction form
   21,978.72/30,330.63 = 11,907.23/x
3. Step 3: Cross multiply
   21,978.72x = 30,330.63 × 11,907.23
4. Step 4: Simplify right side
   21,978.72x = 361,153,635.80
5. Step 5: Solve for x
   x = 361,153,635.80/21,978.72
6. Step 6: Final answer
   x = 16,431.97