Finding the Fourth Proportional to 3,978.66, 5,968.94 and 3,912.55

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.66 : 5,968.94 = 3,912.55 : x
2. Step 2: Convert to fraction form
   3,978.66/5,968.94 = 3,912.55/x
3. Step 3: Cross multiply
   3,978.66x = 5,968.94 × 3,912.55
4. Step 4: Simplify right side
   3,978.66x = 23,353,741.71
5. Step 5: Solve for x
   x = 23,353,741.71/3,978.66
6. Step 6: Final answer
   x = 5,869.75