Finding the Fourth Proportional to 1,356.76, 1,871.79 and 885.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,356.76 : 1,871.79 = 885.20 : x
2. Step 2: Convert to fraction form
   1,356.76/1,871.79 = 885.20/x
3. Step 3: Cross multiply
   1,356.76x = 1,871.79 × 885.20
4. Step 4: Simplify right side
   1,356.76x = 1,656,906.30
5. Step 5: Solve for x
   x = 1,656,906.30/1,356.76
6. Step 6: Final answer
   x = 1,221.23