Finding the Fourth Proportional to 28,404.50, 39,183.30 and 21,678.41

Step by Step Solution

1. Step 1: Write the proportion equation
   28,404.50 : 39,183.30 = 21,678.41 : x
2. Step 2: Convert to fraction form
   28,404.50/39,183.30 = 21,678.41/x
3. Step 3: Cross multiply
   28,404.50x = 39,183.30 × 21,678.41
4. Step 4: Simplify right side
   28,404.50x = 849,431,642.55
5. Step 5: Solve for x
   x = 849,431,642.55/28,404.50
6. Step 6: Final answer
   x = 29,904.83