Finding the Fourth Proportional to 1,569.42, 2,165.80 and 861.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,569.42 : 2,165.80 = 861.27 : x
2. Step 2: Convert to fraction form
   1,569.42/2,165.80 = 861.27/x
3. Step 3: Cross multiply
   1,569.42x = 2,165.80 × 861.27
4. Step 4: Simplify right side
   1,569.42x = 1,865,338.57
5. Step 5: Solve for x
   x = 1,865,338.57/1,569.42
6. Step 6: Final answer
   x = 1,188.55