Finding the Fourth Proportional to 13,148.81, 19,629.54 and 12,687.47

Step by Step Solution

1. Step 1: Write the proportion equation
   13,148.81 : 19,629.54 = 12,687.47 : x
2. Step 2: Convert to fraction form
   13,148.81/19,629.54 = 12,687.47/x
3. Step 3: Cross multiply
   13,148.81x = 19,629.54 × 12,687.47
4. Step 4: Simplify right side
   13,148.81x = 249,049,199.86
5. Step 5: Solve for x
   x = 249,049,199.86/13,148.81
6. Step 6: Final answer
   x = 18,940.82