Finding the Fourth Proportional to 1,085.34, 1,628.01 and 263.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.34 : 1,628.01 = 263.61 : x
2. Step 2: Convert to fraction form
   1,085.34/1,628.01 = 263.61/x
3. Step 3: Cross multiply
   1,085.34x = 1,628.01 × 263.61
4. Step 4: Simplify right side
   1,085.34x = 429,162.77
5. Step 5: Solve for x
   x = 429,162.77/1,085.34
6. Step 6: Final answer
   x = 395.42