Finding the Fourth Proportional to 2,978.72, 4,112.70 and 1,859.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,978.72 : 4,112.70 = 1,859.90 : x
2. Step 2: Convert to fraction form
   2,978.72/4,112.70 = 1,859.90/x
3. Step 3: Cross multiply
   2,978.72x = 4,112.70 × 1,859.90
4. Step 4: Simplify right side
   2,978.72x = 7,649,210.73
5. Step 5: Solve for x
   x = 7,649,210.73/2,978.72
6. Step 6: Final answer
   x = 2,567.95