Finding the Fourth Proportional to 1,085.09, 1,627.76 and 426.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.09 : 1,627.76 = 426.83 : x
2. Step 2: Convert to fraction form
   1,085.09/1,627.76 = 426.83/x
3. Step 3: Cross multiply
   1,085.09x = 1,627.76 × 426.83
4. Step 4: Simplify right side
   1,085.09x = 694,769.73
5. Step 5: Solve for x
   x = 694,769.73/1,085.09
6. Step 6: Final answer
   x = 640.29