Finding the Fourth Proportional to 1,386.32, 1,913.31 and 890.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.32 : 1,913.31 = 890.37 : x
2. Step 2: Convert to fraction form
   1,386.32/1,913.31 = 890.37/x
3. Step 3: Cross multiply
   1,386.32x = 1,913.31 × 890.37
4. Step 4: Simplify right side
   1,386.32x = 1,703,553.82
5. Step 5: Solve for x
   x = 1,703,553.82/1,386.32
6. Step 6: Final answer
   x = 1,228.84