Finding the Fourth Proportional to 21,578.60, 32,359.70 and 8,429.27

Step by Step Solution

1. Step 1: Write the proportion equation
   21,578.60 : 32,359.70 = 8,429.27 : x
2. Step 2: Convert to fraction form
   21,578.60/32,359.70 = 8,429.27/x
3. Step 3: Cross multiply
   21,578.60x = 32,359.70 × 8,429.27
4. Step 4: Simplify right side
   21,578.60x = 272,768,507.69
5. Step 5: Solve for x
   x = 272,768,507.69/21,578.60
6. Step 6: Final answer
   x = 12,640.69