Finding the Fourth Proportional to 1,561.28, 2,154.62 and 862.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.28 : 2,154.62 = 862.72 : x
2. Step 2: Convert to fraction form
   1,561.28/2,154.62 = 862.72/x
3. Step 3: Cross multiply
   1,561.28x = 2,154.62 × 862.72
4. Step 4: Simplify right side
   1,561.28x = 1,858,833.77
5. Step 5: Solve for x
   x = 1,858,833.77/1,561.28
6. Step 6: Final answer
   x = 1,190.58