Finding the Fourth Proportional to 3,891.90, 5,866.60 and 3,666.18

Step by Step Solution

1. Step 1: Write the proportion equation
   3,891.90 : 5,866.60 = 3,666.18 : x
2. Step 2: Convert to fraction form
   3,891.90/5,866.60 = 3,666.18/x
3. Step 3: Cross multiply
   3,891.90x = 5,866.60 × 3,666.18
4. Step 4: Simplify right side
   3,891.90x = 21,508,011.59
5. Step 5: Solve for x
   x = 21,508,011.59/3,891.90
6. Step 6: Final answer
   x = 5,526.35