Finding the Fourth Proportional to 1,561.82, 2,155.28 and 863.19

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.82 : 2,155.28 = 863.19 : x
2. Step 2: Convert to fraction form
   1,561.82/2,155.28 = 863.19/x
3. Step 3: Cross multiply
   1,561.82x = 2,155.28 × 863.19
4. Step 4: Simplify right side
   1,561.82x = 1,860,411.83
5. Step 5: Solve for x
   x = 1,860,411.83/1,561.82
6. Step 6: Final answer
   x = 1,191.19