Finding the Fourth Proportional to 1,101.35, 1,521.39 and 855.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,101.35 : 1,521.39 = 855.81 : x
2. Step 2: Convert to fraction form
   1,101.35/1,521.39 = 855.81/x
3. Step 3: Cross multiply
   1,101.35x = 1,521.39 × 855.81
4. Step 4: Simplify right side
   1,101.35x = 1,302,020.78
5. Step 5: Solve for x
   x = 1,302,020.78/1,101.35
6. Step 6: Final answer
   x = 1,182.21