Finding the Fourth Proportional to 2,100.20, 3,147.99 and 866.94

Step by Step Solution

1. Step 1: Write the proportion equation
   2,100.20 : 3,147.99 = 866.94 : x
2. Step 2: Convert to fraction form
   2,100.20/3,147.99 = 866.94/x
3. Step 3: Cross multiply
   2,100.20x = 3,147.99 × 866.94
4. Step 4: Simplify right side
   2,100.20x = 2,729,105.83
5. Step 5: Solve for x
   x = 2,729,105.83/2,100.20
6. Step 6: Final answer
   x = 1,299.45