Finding the Fourth Proportional to 1,388.82, 1,916.84 and 892.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.82 : 1,916.84 = 892.09 : x
2. Step 2: Convert to fraction form
   1,388.82/1,916.84 = 892.09/x
3. Step 3: Cross multiply
   1,388.82x = 1,916.84 × 892.09
4. Step 4: Simplify right side
   1,388.82x = 1,709,993.80
5. Step 5: Solve for x
   x = 1,709,993.80/1,388.82
6. Step 6: Final answer
   x = 1,231.26