Finding the Fourth Proportional to 1,569.39, 2,165.81 and 861.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,569.39 : 2,165.81 = 861.25 : x
2. Step 2: Convert to fraction form
   1,569.39/2,165.81 = 861.25/x
3. Step 3: Cross multiply
   1,569.39x = 2,165.81 × 861.25
4. Step 4: Simplify right side
   1,569.39x = 1,865,307.52
5. Step 5: Solve for x
   x = 1,865,307.52/1,569.39
6. Step 6: Final answer
   x = 1,188.56