Finding the Fourth Proportional to 1,561.59, 2,155.01 and 863.01

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.59 : 2,155.01 = 863.01 : x
2. Step 2: Convert to fraction form
   1,561.59/2,155.01 = 863.01/x
3. Step 3: Cross multiply
   1,561.59x = 2,155.01 × 863.01
4. Step 4: Simplify right side
   1,561.59x = 1,859,790.87
5. Step 5: Solve for x
   x = 1,859,790.87/1,561.59
6. Step 6: Final answer
   x = 1,190.96