Finding the Fourth Proportional to 21,224, 29,291.82 and 12,840.56

Step by Step Solution

1. Step 1: Write the proportion equation
   21,224 : 29,291.82 = 12,840.56 : x
2. Step 2: Convert to fraction form
   21,224/29,291.82 = 12,840.56/x
3. Step 3: Cross multiply
   21,224x = 29,291.82 × 12,840.56
4. Step 4: Simplify right side
   21,224x = 376,123,372.22
5. Step 5: Solve for x
   x = 376,123,372.22/21,224
6. Step 6: Final answer
   x = 17,721.61