Finding the Fourth Proportional to 1,561.46, 2,154.78 and 898.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.46 : 2,154.78 = 898.31 : x
2. Step 2: Convert to fraction form
   1,561.46/2,154.78 = 898.31/x
3. Step 3: Cross multiply
   1,561.46x = 2,154.78 × 898.31
4. Step 4: Simplify right side
   1,561.46x = 1,935,649.65
5. Step 5: Solve for x
   x = 1,935,649.65/1,561.46
6. Step 6: Final answer
   x = 1,239.64