Finding the Fourth Proportional to 12,978.32, 19,464.24 and 4,215.74

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.32 : 19,464.24 = 4,215.74 : x
2. Step 2: Convert to fraction form
   12,978.32/19,464.24 = 4,215.74/x
3. Step 3: Cross multiply
   12,978.32x = 19,464.24 × 4,215.74
4. Step 4: Simplify right side
   12,978.32x = 82,056,175.14
5. Step 5: Solve for x
   x = 82,056,175.14/12,978.32
6. Step 6: Final answer
   x = 6,322.56