Finding the Fourth Proportional to 6,139.74, 9,210.42 and 1,978.38

Step by Step Solution

1. Step 1: Write the proportion equation
   6,139.74 : 9,210.42 = 1,978.38 : x
2. Step 2: Convert to fraction form
   6,139.74/9,210.42 = 1,978.38/x
3. Step 3: Cross multiply
   6,139.74x = 9,210.42 × 1,978.38
4. Step 4: Simplify right side
   6,139.74x = 18,221,710.72
5. Step 5: Solve for x
   x = 18,221,710.72/6,139.74
6. Step 6: Final answer
   x = 2,967.83