Finding the Fourth Proportional to 12,979.78, 19,491.52 and 12,877.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,979.78 : 19,491.52 = 12,877.72 : x
2. Step 2: Convert to fraction form
   12,979.78/19,491.52 = 12,877.72/x
3. Step 3: Cross multiply
   12,979.78x = 19,491.52 × 12,877.72
4. Step 4: Simplify right side
   12,979.78x = 251,006,336.93
5. Step 5: Solve for x
   x = 251,006,336.93/12,979.78
6. Step 6: Final answer
   x = 19,338.26