Finding the Fourth Proportional to 8,978.39, 12,390.39 and 5,201.56

Step by Step Solution

1. Step 1: Write the proportion equation
   8,978.39 : 12,390.39 = 5,201.56 : x
2. Step 2: Convert to fraction form
   8,978.39/12,390.39 = 5,201.56/x
3. Step 3: Cross multiply
   8,978.39x = 12,390.39 × 5,201.56
4. Step 4: Simplify right side
   8,978.39x = 64,449,357.01
5. Step 5: Solve for x
   x = 64,449,357.01/8,978.39
6. Step 6: Final answer
   x = 7,178.28