Finding the Fourth Proportional to 21,407.10, 29,529.59 and 12,453.56

Step by Step Solution

1. Step 1: Write the proportion equation
   21,407.10 : 29,529.59 = 12,453.56 : x
2. Step 2: Convert to fraction form
   21,407.10/29,529.59 = 12,453.56/x
3. Step 3: Cross multiply
   21,407.10x = 29,529.59 × 12,453.56
4. Step 4: Simplify right side
   21,407.10x = 367,748,520.84
5. Step 5: Solve for x
   x = 367,748,520.84/21,407.10
6. Step 6: Final answer
   x = 17,178.81