Finding the Fourth Proportional to 2,105.67, 2,906.25 and 1,221.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.67 : 2,906.25 = 1,221.42 : x
2. Step 2: Convert to fraction form
   2,105.67/2,906.25 = 1,221.42/x
3. Step 3: Cross multiply
   2,105.67x = 2,906.25 × 1,221.42
4. Step 4: Simplify right side
   2,105.67x = 3,549,751.88
5. Step 5: Solve for x
   x = 3,549,751.88/2,105.67
6. Step 6: Final answer
   x = 1,685.81