Finding the Fourth Proportional to 3,978.69, 5,966.15 and 1,637.79

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.69 : 5,966.15 = 1,637.79 : x
2. Step 2: Convert to fraction form
   3,978.69/5,966.15 = 1,637.79/x
3. Step 3: Cross multiply
   3,978.69x = 5,966.15 × 1,637.79
4. Step 4: Simplify right side
   3,978.69x = 9,771,292.62
5. Step 5: Solve for x
   x = 9,771,292.62/3,978.69
6. Step 6: Final answer
   x = 2,455.91