Finding the Fourth Proportional to 1,561.73, 2,155.20 and 1,229.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.73 : 2,155.20 = 1,229.54 : x
2. Step 2: Convert to fraction form
   1,561.73/2,155.20 = 1,229.54/x
3. Step 3: Cross multiply
   1,561.73x = 2,155.20 × 1,229.54
4. Step 4: Simplify right side
   1,561.73x = 2,649,904.61
5. Step 5: Solve for x
   x = 2,649,904.61/1,561.73
6. Step 6: Final answer
   x = 1,696.78