Finding the Fourth Proportional to 5,217.20, 7,198.98 and 2,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   5,217.20 : 7,198.98 = 2,978.72 : x
2. Step 2: Convert to fraction form
   5,217.20/7,198.98 = 2,978.72/x
3. Step 3: Cross multiply
   5,217.20x = 7,198.98 × 2,978.72
4. Step 4: Simplify right side
   5,217.20x = 21,443,745.71
5. Step 5: Solve for x
   x = 21,443,745.71/5,217.20
6. Step 6: Final answer
   x = 4,110.20