Finding the Fourth Proportional to 3,439.37, 5,146.72 and 2,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,439.37 : 5,146.72 = 2,978.72 : x
2. Step 2: Convert to fraction form
   3,439.37/5,146.72 = 2,978.72/x
3. Step 3: Cross multiply
   3,439.37x = 5,146.72 × 2,978.72
4. Step 4: Simplify right side
   3,439.37x = 15,330,637.80
5. Step 5: Solve for x
   x = 15,330,637.80/3,439.37
6. Step 6: Final answer
   x = 4,457.40