Finding the Fourth Proportional to 21,978.79, 30,330.69 and 11,907.48

Step by Step Solution

1. Step 1: Write the proportion equation
   21,978.79 : 30,330.69 = 11,907.48 : x
2. Step 2: Convert to fraction form
   21,978.79/30,330.69 = 11,907.48/x
3. Step 3: Cross multiply
   21,978.79x = 30,330.69 × 11,907.48
4. Step 4: Simplify right side
   21,978.79x = 361,162,153.65
5. Step 5: Solve for x
   x = 361,162,153.65/21,978.79
6. Step 6: Final answer
   x = 16,432.31