Finding the Fourth Proportional to 3,978.70, 5,490.85 and 2,300.42

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.70 : 5,490.85 = 2,300.42 : x
2. Step 2: Convert to fraction form
   3,978.70/5,490.85 = 2,300.42/x
3. Step 3: Cross multiply
   3,978.70x = 5,490.85 × 2,300.42
4. Step 4: Simplify right side
   3,978.70x = 12,631,261.16
5. Step 5: Solve for x
   x = 12,631,261.16/3,978.70
6. Step 6: Final answer
   x = 3,174.72