Finding the Fourth Proportional to 1,561.74, 2,155.16 and 863.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.74 : 2,155.16 = 863.10 : x
2. Step 2: Convert to fraction form
   1,561.74/2,155.16 = 863.10/x
3. Step 3: Cross multiply
   1,561.74x = 2,155.16 × 863.10
4. Step 4: Simplify right side
   1,561.74x = 1,860,118.60
5. Step 5: Solve for x
   x = 1,860,118.60/1,561.74
6. Step 6: Final answer
   x = 1,191.06