Finding the Fourth Proportional to 12,978.74, 19,468.38 and 4,659.30

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.74 : 19,468.38 = 4,659.30 : x
2. Step 2: Convert to fraction form
   12,978.74/19,468.38 = 4,659.30/x
3. Step 3: Cross multiply
   12,978.74x = 19,468.38 × 4,659.30
4. Step 4: Simplify right side
   12,978.74x = 90,709,022.93
5. Step 5: Solve for x
   x = 90,709,022.93/12,978.74
6. Step 6: Final answer
   x = 6,989.05