Finding the Fourth Proportional to 1,086.57, 1,627.57 and 854.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.57 : 1,627.57 = 854.35 : x
2. Step 2: Convert to fraction form
   1,086.57/1,627.57 = 854.35/x
3. Step 3: Cross multiply
   1,086.57x = 1,627.57 × 854.35
4. Step 4: Simplify right side
   1,086.57x = 1,390,514.43
5. Step 5: Solve for x
   x = 1,390,514.43/1,086.57
6. Step 6: Final answer
   x = 1,279.73