Finding the Fourth Proportional to 21,328.59, 29,417.28 and 12,830.07

Step by Step Solution

1. Step 1: Write the proportion equation
   21,328.59 : 29,417.28 = 12,830.07 : x
2. Step 2: Convert to fraction form
   21,328.59/29,417.28 = 12,830.07/x
3. Step 3: Cross multiply
   21,328.59x = 29,417.28 × 12,830.07
4. Step 4: Simplify right side
   21,328.59x = 377,425,550.37
5. Step 5: Solve for x
   x = 377,425,550.37/21,328.59
6. Step 6: Final answer
   x = 17,695.76