Finding the Fourth Proportional to 2,105.99, 2,905.43 and 1,221.27

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.99 : 2,905.43 = 1,221.27 : x
2. Step 2: Convert to fraction form
   2,105.99/2,905.43 = 1,221.27/x
3. Step 3: Cross multiply
   2,105.99x = 2,905.43 × 1,221.27
4. Step 4: Simplify right side
   2,105.99x = 3,548,314.50
5. Step 5: Solve for x
   x = 3,548,314.50/2,105.99
6. Step 6: Final answer
   x = 1,684.87