Finding the Fourth Proportional to 2,105.44, 2,905.52 and 1,221.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.44 : 2,905.52 = 1,221.78 : x
2. Step 2: Convert to fraction form
   2,105.44/2,905.52 = 1,221.78/x
3. Step 3: Cross multiply
   2,105.44x = 2,905.52 × 1,221.78
4. Step 4: Simplify right side
   2,105.44x = 3,549,906.23
5. Step 5: Solve for x
   x = 3,549,906.23/2,105.44
6. Step 6: Final answer
   x = 1,686.06