Finding the Fourth Proportional to 1,085.51, 1,627.88 and 392.00

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.51 : 1,627.88 = 392.00 : x
2. Step 2: Convert to fraction form
   1,085.51/1,627.88 = 392.00/x
3. Step 3: Cross multiply
   1,085.51x = 1,627.88 × 392.00
4. Step 4: Simplify right side
   1,085.51x = 638,118.86
5. Step 5: Solve for x
   x = 638,118.86/1,085.51
6. Step 6: Final answer
   x = 587.85