Finding the Fourth Proportional to 21,830.50, 30,128.52 and 13,447

Step by Step Solution

1. Step 1: Write the proportion equation
   21,830.50 : 30,128.52 = 13,447 : x
2. Step 2: Convert to fraction form
   21,830.50/30,128.52 = 13,447/x
3. Step 3: Cross multiply
   21,830.50x = 30,128.52 × 13,447
4. Step 4: Simplify right side
   21,830.50x = 405,138,208.44
5. Step 5: Solve for x
   x = 405,138,208.44/21,830.50
6. Step 6: Final answer
   x = 18,558.36