Finding the Fourth Proportional to 12,978.56, 19,468.48 and 3,618.56

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.56 : 19,468.48 = 3,618.56 : x
2. Step 2: Convert to fraction form
   12,978.56/19,468.48 = 3,618.56/x
3. Step 3: Cross multiply
   12,978.56x = 19,468.48 × 3,618.56
4. Step 4: Simplify right side
   12,978.56x = 70,447,862.99
5. Step 5: Solve for x
   x = 70,447,862.99/12,978.56
6. Step 6: Final answer
   x = 5,428.02