Finding the Fourth Proportional to 2,978.47, 4,447.65 and 2,431.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,978.47 : 4,447.65 = 2,431.72 : x
2. Step 2: Convert to fraction form
   2,978.47/4,447.65 = 2,431.72/x
3. Step 3: Cross multiply
   2,978.47x = 4,447.65 × 2,431.72
4. Step 4: Simplify right side
   2,978.47x = 10,815,405.06
5. Step 5: Solve for x
   x = 10,815,405.06/2,978.47
6. Step 6: Final answer
   x = 3,631.20