Finding the Fourth Proportional to 21,453.53, 29,607.80 and 12,958.25

Step by Step Solution

1. Step 1: Write the proportion equation
   21,453.53 : 29,607.80 = 12,958.25 : x
2. Step 2: Convert to fraction form
   21,453.53/29,607.80 = 12,958.25/x
3. Step 3: Cross multiply
   21,453.53x = 29,607.80 × 12,958.25
4. Step 4: Simplify right side
   21,453.53x = 383,665,061.52
5. Step 5: Solve for x
   x = 383,665,061.52/21,453.53
6. Step 6: Final answer
   x = 17,883.54