Finding the Fourth Proportional to 3,978.05, 5,491.18 and 3,416.26

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.05 : 5,491.18 = 3,416.26 : x
2. Step 2: Convert to fraction form
   3,978.05/5,491.18 = 3,416.26/x
3. Step 3: Cross multiply
   3,978.05x = 5,491.18 × 3,416.26
4. Step 4: Simplify right side
   3,978.05x = 18,759,276.32
5. Step 5: Solve for x
   x = 18,759,276.32/3,978.05
6. Step 6: Final answer
   x = 4,715.70