Finding the Fourth Proportional to 1,390.38, 1,917.82 and 892.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.38 : 1,917.82 = 892.23 : x
2. Step 2: Convert to fraction form
   1,390.38/1,917.82 = 892.23/x
3. Step 3: Cross multiply
   1,390.38x = 1,917.82 × 892.23
4. Step 4: Simplify right side
   1,390.38x = 1,711,136.54
5. Step 5: Solve for x
   x = 1,711,136.54/1,390.38
6. Step 6: Final answer
   x = 1,230.70