Finding the Fourth Proportional to 3,978.79, 5,488.21 and 2,564.33

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.79 : 5,488.21 = 2,564.33 : x
2. Step 2: Convert to fraction form
   3,978.79/5,488.21 = 2,564.33/x
3. Step 3: Cross multiply
   3,978.79x = 5,488.21 × 2,564.33
4. Step 4: Simplify right side
   3,978.79x = 14,073,581.55
5. Step 5: Solve for x
   x = 14,073,581.55/3,978.79
6. Step 6: Final answer
   x = 3,537.15