Finding the Fourth Proportional to 1,585.42, 2,187.90 and 886.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,585.42 : 2,187.90 = 886.78 : x
2. Step 2: Convert to fraction form
   1,585.42/2,187.90 = 886.78/x
3. Step 3: Cross multiply
   1,585.42x = 2,187.90 × 886.78
4. Step 4: Simplify right side
   1,585.42x = 1,940,185.96
5. Step 5: Solve for x
   x = 1,940,185.96/1,585.42
6. Step 6: Final answer
   x = 1,223.77