Finding the Fourth Proportional to 2,105.45, 2,904.89 and 1,221.23

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.45 : 2,904.89 = 1,221.23 : x
2. Step 2: Convert to fraction form
   2,105.45/2,904.89 = 1,221.23/x
3. Step 3: Cross multiply
   2,105.45x = 2,904.89 × 1,221.23
4. Step 4: Simplify right side
   2,105.45x = 3,547,518.18
5. Step 5: Solve for x
   x = 3,547,518.18/2,105.45
6. Step 6: Final answer
   x = 1,684.93