Finding the Fourth Proportional to 1,389.71, 1,917.79 and 892.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.71 : 1,917.79 = 892.54 : x
2. Step 2: Convert to fraction form
   1,389.71/1,917.79 = 892.54/x
3. Step 3: Cross multiply
   1,389.71x = 1,917.79 × 892.54
4. Step 4: Simplify right side
   1,389.71x = 1,711,709.47
5. Step 5: Solve for x
   x = 1,711,709.47/1,389.71
6. Step 6: Final answer
   x = 1,231.70