Finding the Fourth Proportional to 12,978.82, 19,467.96 and 4,213.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.82 : 19,467.96 = 4,213.72 : x
2. Step 2: Convert to fraction form
   12,978.82/19,467.96 = 4,213.72/x
3. Step 3: Cross multiply
   12,978.82x = 19,467.96 × 4,213.72
4. Step 4: Simplify right side
   12,978.82x = 82,032,532.41
5. Step 5: Solve for x
   x = 82,032,532.41/12,978.82
6. Step 6: Final answer
   x = 6,320.49