Finding the Fourth Proportional to 8,978.72, 12,387.06 and 5,574.08

Step by Step Solution

1. Step 1: Write the proportion equation
   8,978.72 : 12,387.06 = 5,574.08 : x
2. Step 2: Convert to fraction form
   8,978.72/12,387.06 = 5,574.08/x
3. Step 3: Cross multiply
   8,978.72x = 12,387.06 × 5,574.08
4. Step 4: Simplify right side
   8,978.72x = 69,046,494.37
5. Step 5: Solve for x
   x = 69,046,494.37/8,978.72
6. Step 6: Final answer
   x = 7,690.02