Finding the Fourth Proportional to 1,561.57, 2,155.42 and 898.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.57 : 2,155.42 = 898.89 : x
2. Step 2: Convert to fraction form
   1,561.57/2,155.42 = 898.89/x
3. Step 3: Cross multiply
   1,561.57x = 2,155.42 × 898.89
4. Step 4: Simplify right side
   1,561.57x = 1,937,485.48
5. Step 5: Solve for x
   x = 1,937,485.48/1,561.57
6. Step 6: Final answer
   x = 1,240.73