Finding the Fourth Proportional to 1,561.94, 2,154.96 and 898.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.94 : 2,154.96 = 898.55 : x
2. Step 2: Convert to fraction form
   1,561.94/2,154.96 = 898.55/x
3. Step 3: Cross multiply
   1,561.94x = 2,154.96 × 898.55
4. Step 4: Simplify right side
   1,561.94x = 1,936,339.31
5. Step 5: Solve for x
   x = 1,936,339.31/1,561.94
6. Step 6: Final answer
   x = 1,239.70