Finding the Fourth Proportional to 3,970.76, 5,478.86 and 2,398.86

Step by Step Solution

1. Step 1: Write the proportion equation
   3,970.76 : 5,478.86 = 2,398.86 : x
2. Step 2: Convert to fraction form
   3,970.76/5,478.86 = 2,398.86/x
3. Step 3: Cross multiply
   3,970.76x = 5,478.86 × 2,398.86
4. Step 4: Simplify right side
   3,970.76x = 13,143,024.10
5. Step 5: Solve for x
   x = 13,143,024.10/3,970.76
6. Step 6: Final answer
   x = 3,309.95