Finding the Fourth Proportional to 1,561.83, 2,155.56 and 898.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.83 : 2,155.56 = 898.53 : x
2. Step 2: Convert to fraction form
   1,561.83/2,155.56 = 898.53/x
3. Step 3: Cross multiply
   1,561.83x = 2,155.56 × 898.53
4. Step 4: Simplify right side
   1,561.83x = 1,936,835.33
5. Step 5: Solve for x
   x = 1,936,835.33/1,561.83
6. Step 6: Final answer
   x = 1,240.11