Finding the Fourth Proportional to 1,208.81, 1,812.53 and 1,105.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,208.81 : 1,812.53 = 1,105.61 : x
2. Step 2: Convert to fraction form
   1,208.81/1,812.53 = 1,105.61/x
3. Step 3: Cross multiply
   1,208.81x = 1,812.53 × 1,105.61
4. Step 4: Simplify right side
   1,208.81x = 2,003,936.70
5. Step 5: Solve for x
   x = 2,003,936.70/1,208.81
6. Step 6: Final answer
   x = 1,657.78