Finding the Fourth Proportional to 2,978.70, 4,470.78 and 2,800.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,978.70 : 4,470.78 = 2,800.10 : x
2. Step 2: Convert to fraction form
   2,978.70/4,470.78 = 2,800.10/x
3. Step 3: Cross multiply
   2,978.70x = 4,470.78 × 2,800.10
4. Step 4: Simplify right side
   2,978.70x = 12,518,608.72
5. Step 5: Solve for x
   x = 12,518,608.72/2,978.70
6. Step 6: Final answer
   x = 4,202.71