Finding the Fourth Proportional to 15,285.57, 21,106.56 and 12,453.42

Step by Step Solution

1. Step 1: Write the proportion equation
   15,285.57 : 21,106.56 = 12,453.42 : x
2. Step 2: Convert to fraction form
   15,285.57/21,106.56 = 12,453.42/x
3. Step 3: Cross multiply
   15,285.57x = 21,106.56 × 12,453.42
4. Step 4: Simplify right side
   15,285.57x = 262,848,856.44
5. Step 5: Solve for x
   x = 262,848,856.44/15,285.57
6. Step 6: Final answer
   x = 17,195.88