Finding the Fourth Proportional to 2,105.27, 2,905.36 and 1,220.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.27 : 2,905.36 = 1,220.88 : x
2. Step 2: Convert to fraction form
   2,105.27/2,905.36 = 1,220.88/x
3. Step 3: Cross multiply
   2,105.27x = 2,905.36 × 1,220.88
4. Step 4: Simplify right side
   2,105.27x = 3,547,092.86
5. Step 5: Solve for x
   x = 3,547,092.86/2,105.27
6. Step 6: Final answer
   x = 1,684.87